Pest Control

Cockroach

Cockroaches are eminently tropical but certain species have become widely disseminated through commerce and are now cosmopolitan. They are nocturnal in habit and attack food, paper, clothing, shoes, and dead insects. The German cockroach prefers a warm and moist environment. Consequently it has become a pest of kitchens, and restaurants, where food, warmth and moisture provide the necessary ecological requirements. The oriental cockroach on the other hand prefers cooler areas. These are therefore found under coverings, in bathrooms, toilets, and sinks, where large numbers congregate around sources of water. The American cockroach infests all houses in store-rooms, kitchens, cupboards, and libraries, while the brown banded cockroach which can fly prefers locations high up in the rooms.

Inspection and treatment should go together whether a complaint has been received or not. All the possible hiding places of cockroaches must be thoroughly investigated. These places would probably be dark corners. Your inspection should begin where the patient or staff thinks he or she has seen one. You must be equipped with a flash light and a hypodermic syringe with a flushing agent to flush crevices and areas behind in-built furniture where the flash light cannot reach. Remove the drawers and shelves of the furniture wherever possible and inspect the inside of the furniture thoroughly. Check calendars and pictures on the walls, electrical appliances such as the refrigerators, wall clocks, ovens, food mixers, and coffee blenders.

  Other places that need attention and which we tend to overlook are:

• - Rubber and gasket lining in the refrigerator and other appliances
• - Splash plate - in walls behind ovens and stoves
• - Baseboard - forming a base around the room up to 8” above floor level
• - Linoleum - corners and around the walls
• - Carpets - underneath; to be rolled up
• - Panels - on the walls - to be injected wherever there are cracks
• - Fuse box, behind sinks, light fixtures etc

Sprinkle Baygon bait in places where cockroaches congregate, rest or hide, such as dark corners of closets, base of walls in basements, under sinks, around drain pipes, upon shelves, etc. However, Baygon is toxic, and can harm children and pets if accidentally ingested. Bay leaves, cucumber slices and garlic are natural deterrents for roaches, and are far safer to use. Also, spraying cockroaches directly with soapy water kills them instantly. Hence keeping a spray of soapy water handy near cockroach infested areas is useful.Sealing of small cracks and crevices in walls, around window frames and in the floor are also proofing measures that would help to prevent nesting of cockroaches.

Fly

As a rule flies are of small or moderate size; some species are even minute, measuring one millimeter long, while some Australian robber flies exceed three inches in wing-expanse with a body length of one and three-quarter inches. The majority of flies are diurnal and frequently fly around for nectar or haunt decaying organic matter of diverse kinds. Many flies do not visit flowers but are found on foliage, tree trunks, fallen logs, in grass, on the ground, or on the mud where they seek food. The primitive blood sucking species, such as the mosquito and the sand fly are mostly crepuscular (active at dawn or dusk) or nocturnal. Many species are predacious on smaller insects, mites, and small worms. A relatively small number have acquired the habit of blood sucking, confined mostly to the female of the species. A small number of the blood sucking species are of great importance to us on account of their ability to transmit various diseases to man and other animals. The pathogenic organism of malaria, yellow fever, elephantiasis, and other diseases are transmitted from animal to man and from man to man through the medium of biting flies, and cannot be contracted in any other way.

This species is probably the most familiar and certainly the most widely distributed of all insects. It has accompanied man everywhere and has adapted itself to breeding in a variety of rejected food and excrement of man and his domestic animals.

  It would be difficult to exaggerate the importance of the Common Housefly as a pest in homes. This is on account of its importance as a carrier of disease brought about by its habit of flying between human faeces and human food. The disease organisms of typhoid, dysentery, summer diarrhea, and probably infantile paralysis are transferred from faecal matter to food by vomit drops in fly excrement or by organisms adhering to the fly’s feet. The eggs of parasitic worms are also transferred in this way. In tropical and sub-tropical areas, in addition to these diseases the housefly is also responsible for the spread of cholera, and opthalmia.

Exclusion has been an effective method of fly control for many years. Putting up mesh screens made of any metal are helpful. Screens if properly maintained provide excellent control of flies.

  Mint is a natural repellent for flies. Small sachets of crushed mint left around the ward will keep flies away. Bay leaves, cloves and eucalyptus oil hung on windows in small sachets will also keep the flies away.

Fly sprays and household sprays are synonymous since a spray that controls flies will also control other insects. There are three kinds of sprays in the market - the space spray which includes aerosols, the surface or residual spray which may be pressurised and the combination space and residual spray. Space sprays are applied as a mist into the air and must be in contact with the insect at the time of spraying. They provide quick knockdown and fast results but temporary control. An aerosol spray sprays the insecticidal ingredients which are dispersed by means of the vapour pressure of liquefied gas rather than the pressure of compressed air. Surface or residual sprays may have a petroleum or water base. They are applied on surfaces as a wet spray rather than a mist and they leave a toxic layer of either crystals or film on the evaporation of the carrier. Surface sprays provide relatively slow knockdowns but long lasting control against non-resistant flies and do not have to come in contact with the insect at the time of spraying in order to be effective. Residual sprays are applied to surfaces frequented by houseflies such as light fixtures, window screens and walls. When a residual spray is used as a space spray, the large amount of toxicant becomes hazardous to the user, and may contaminate food as well.

Pyrethrum: This is the most common ingredient in a fly spray. At recommended dosage it is the safest toxicants and has exceptionally fast knockdown effect. It has the disadvantage of not killing all the insects knocked down.

Allenthrin: This chemical is often referred to as synthetic pyrethrins. It has knockdown and mortality characteristics similar to natural pyrethrins when used against flying insects in space sprays.

Residual sprays: DDT was considered to be very effective until 1950, but by then the flies had become resistant to this toxicant. Today the most common toxicant used is Malathion and diazinon, but the housefly is becoming resistant to these toxicants too.

Baygon bait: there are many fly killing insecticides in the market, however many of them do not solve the real problem of doing their work – that of bringing into contact the fly and the insecticide. The ideal answer to this is the ready-to-use Baygon Bait. It first attracts, and then kills the fly.

The baygon bait has the following advantages:

• The dry granular form makes application very convenient for even unskilled labour to sprinkle. No material for dilution or equipment is needed
• The application can be limited to areas of heavy infestation which are easily located. This avoids waste of material and labour.
• Baygon also controls flies which have developed resistance to the action of chlorinated hydrocarbon and organo-phosphorous insecticides.
• The 2% formulation of Baygon bait has a relatively low order of toxicity to human beings, yet is powerful enough to achieve extremely good results in a few minutes of application. The undisturbed bait remains effective for a very long time.

Sprinkle Baygon bait wherever flies congregate. Particular care should be taken to apply the bait around refuse dumps, garbage heaps, market and slaughter house refuse, around cess pools and other similar areas.

  Baygon bait can also be used by dissolving the bait in water and sprinkling or brushing the solution along the walls and on the floor avoiding direct contact with food stuff.

The presence of houseflies is an indication of our failure to properly dispose off manure, garbage, sewage, food wastes, human excrement dead animals or other organic waste. Therefore proper environmental sanitation is fundamental to successful fly control and fly breeding can be prevented by simple practice of burying such organic matter or by drying it so that its moisture content is below that of larvae development. More importantly, flies cannot breed in thinly scattered material because it dries out and there is no fermentation. Open outdoor toilets are the biggest menace from the stand-point of fly-borne diseases. Where privies cannot be avoided, they should be made as fly-proof as possible and the refuse kept covered by daily applications of waste crankcase oil or liberal amounts of lime.

  Electric flycatcher units that have UV- light emitting fluorescent tubes can do flying insect monitoring.

Silverfish

This primitive wingless insect is so called on account of its shining grey colouration, its sinuous movements, and its quick darts to cover when it is disturbed. The silverfish is nocturnal, shuns light and is most often seen when uncovered in dampish places like the kitchen and the scullery. It is able to walk up rough vertical surfaces such as wall paper and plaster, but unable to do the same on smooth surfaces like glass and porcelain. Hence it gets trapped in wash basins and bathrooms.

  The silverfish is responsible for little actual damage. It feeds on carbohydrate substances such as starch used for wall paper paste and is recorded as biting small irregular shaped holes in linen, cotton and artificial silk. Its carbohydrate diet is supplemented by protein from dead insects and glues used in book binding. Silverfish is not of great economic importance, but is an unpleasant inhabitant in the hospital and in hospital library and needs to be attended to.

Insecticides such as DDT, chlordane, dieldrin, and lindane formerly used for the control of silverfish are no longer registered for use. Although liquids, dust or baits can be used for the control of silverfish, liquids are preferred in visible or exposed areas of the home where dusts or baits may present an undue hazard to children or pets. Dusts can be used in attics, basements, and places where their use is not potentially hazardous.

  In controlling silverfish, the insecticide will be most effective when applied where the insect is most commonly seen. The silverfish commonly occurs in damp areas such as behind or beneath kitchen sinks, beneath or behind cabinet shelves, and inside cupboards and linen closets. Particular attention should be paid to inject small amounts of liquid into or dusts into crevices and cracks formed by shelves, loose moulding or floor tiles, and loose drawer glides. Silverfish are commonly found around book shelves.

These shelves should therefore receive the crack and crevice injections. Caution must be exercised when applying liquids, as the liquid may stain the books especially when water based sprays are used. When it is not possible to use either sprays or dust, then it is advisable to sprinkle bait on the shelves. A small amount of bait, bait dispenser, or bait pellets can be put in the corner of the bookshelves.

  Silverfish can be easily trapped in small glass containers. Wrap the outside with tape. Silverfish can easily climb on rough surfaces, so they can climb up and fall in. They will be trapped inside because they cannot climb smooth surfaces. Drown them in soapy water. However the best preventive control is to remedy the damp conditions.

Lizards

Lizards are typically dry land animals loving the sun and its heat. They are four-legged animals and are capable of very active movements. Usually they are very small and slender creatures. The common garden lizards have a very long tail. The “flying dragon” of India, Draco, is able to hop from branch to branch of the trees that it inhabits. The ordinary wall lizard or gecko, is equipped with vacuum - cupped toes which help them to chase insects along the walls and ceilings of the rooms. A very interesting protective feature of these lizards is the power to break off their tails automatically. This power of automatically breaking off parts of the body is called autotomy.

Lizard control is usually carried out in the warmer periods of the year. Lizards are cold blooded animals and hence in the cold season they tend to hibernate in the warm corners of the house to restore their body temperature. During the warmer periods they come out and can be seen crawling up and down the walls. They usually come out after dusk as they feed on smaller insects that fly around the light sources. Lizards are also found in places infested with cockroaches, as they feed them. Usually, places where lizards abound one will rarely see cockroaches.

Lizards are found mostly behind picture frames, curtains, shelves and window frames. They enter the house through the ventilators and windows. Hence the windows and ventilators should be properly meshed. The house should be kept clean and the suspected hiding places should be regularly inspected. As the lizards thrive on insects, the most effective way of controlling lizards is to control the insects in the hospital.

Lizards are carnivorous and prey on other insects. Hence they cannot be controlled using bait. Chemical control of lizards involves spraying of pesticides directly on the reptiles. Chemicals such as dichlorophos, malathion etc. sprayed on the body kills the lizard instantly. However this process is difficult and tiresome in godowns and libraries where there are several lizards and lots of goods or books behind which they can hide. In such places fumigation is recommended. Fumigation is carried out using Aluminum Phosphide or any other approved fumigant.

Bees, wasps and spiders

As a rule bees and wasps are beneficial insects unmindful of the activities of man, as long as man makes it a point to disregard them. However, at times the nests of these insects are made in close proximity of the hospital. Although the sting of wasps and bees is painful, for some persons it may prove to be serious. It may result in severe reaction and even death.

  The honey bee is man’s oldest insect friend and to this insect that we owe honey, beeswax and the fertilization of many of our crop bearing plants. The honey bee is a social insect living in colonies of 20,000 to 80,000.

  As with man, the honey bee too has its periods of depression. On cloudy days when they are unable to forage for nectar, they get “frustrated” and need to “take out their frustration” on others. On these days we need to be cautious.

  Most individuals who fear bees do so because of their potent sting. When the bee stings the sting, poison sac, and several other parts of the bee’s anatomy are torn from the bee’s body and the bee soon dies. The action of the sting takes place instantly. The sting has barbs on it and if it is not immediately removed the reflex action of the muscle attached to the sting drives it deeper into the sting permitting more time for the poison to be discharged. The pain due to the sting gets more acute as the toxin is discharged.

Control

While bees are almost always mild in the swarming stage, it is still advisable to wear a bee veil and to tie the cuffs of trousers tightly to the ankle when trying to trap them. Where the swarm has settled on a limb, the limb may be jerked and the swarm collected in a cardboard box. One should be sure that the queen bee does not remain on the limb. The box is then closed and sealed to prevent the bees from escaping. After taking the box to a distance away from the swarming place it may be opened and the bees set free. If the bees have to be returned to the hive the box is completely sealed and moved at night to where the hive is located. The bees are then transferred the next morning.

  A variety of insecticides are effective including bendiocard, carbaryl, diazinon, malathion and porpoxur. The dust formulation of these products is preferable to spray formulations when bee and wasp nests are in enclosed places. Dust has the advantage of being widely distributed by the insects themselves as they move around in the nest. Sprays kill only those insects which come in contact with the sprayed area. Usually one application is sufficient with activity ceasing in one or two days. Nests should be treated at night to avoid getting stung.

Wasps

The wasp flies above lawns which are infested with beetle grubs, as these grubs are food for the wasp. Wasps appear in the morning and fly all day, retiring early in the evening. These wasps generally do not attack people. You can walk safely through them as they fly around. In order to control them the lawn can be sprayed with carbaryl or the grubs controlled with chloropyrifos or diazinon.

Yellow jackets and hornets

These are the real problems of the wasp world as far as humans are concerned. These social wasps live in colonies which number in thousands.These beneficial insects would not anger man except they like to live in close proximity with us. they nest in attics and voids in the walls where they can go unnoticed for a long time.They usually go outdoors in search of food, but when they are not able to get food, they come into the living area and become a threat to the inhabitants of the place. They feed in trash cans, and enjoy our food they resent our efforts to keep them away from our food. When this happens they need to be controlled.

Prevention

Seal entry points. Searching for and sealing off their point of entry is the best line of defense. Check your house for unsealed vents, torn screens, cracks around windows and door frames and open dampers. Observe the flight path of a wasp, especially in the morning, which may reveal the entry/exit point.

  Any food left outdoors, such as pet food, picnic scraps, open garbage containers or uncovered compost piles should be removed or covered. Wasps imprint food sources, and will continue to search an area for some time after the food has been removed. Be sure to cover drinks and open food containers, keep a lid on the compost and avoid walking barefoot near fruit trees. Remove any fallen fruit rotting on the ground.

  Avoid swatting. Swatting and squashing wasps is counterproductive. When a wasp is squashed, a chemical (pheromone) is released which attracts and incites other nearby wasps. It's best to walk away from a hovering wasp.

Traps

Make a simple water trap

Use a razor knife to cut the top from a 2-liter plastic pop bottle. Cut just above the shoulder of the bottle. Discard the screw top. Fill with water about halfway. Coat the neck with jam, invert it and set back on the bottle. Use two small pieces of tape to hold it in place.

  Wasps will go down the funnel to get the jam, but will find it difficult to get out. Most will drop into the water and drown.

  A few drops of dish soap in the water will make it hard for the wasps to tread water, and will hasten their demise. (You can also add a 1/4 cup of vinegar to the water to discourage honeybees from entering the trap in search of water.)

  Note: In the spring and early summer, wasps are attracted to protein-based baits; use jam or other sweet baits in later summer and into fall.

  Empty the trap daily! As more wasps are caught, they create a raft on which other wasps can survive for a considerable time. Some of these wasps then find purchase on the plastic of the bottle and eventually crawl out. The longer the trap is untended, the more wasps will manage to escape, which may result in swarming.

  The trap will be most effective if set about 4' above ground.

Control

If the nest can be found, control is simple. Simply spray bendiocarb, carbaryl, chloropyrifos, diazinon, or resmethrin into the nest opening of the aerial nesters. Then wet the nest envelope. The nest may be removed in a day or two. For ground nests dust formulation of any of the above insecticides is preferable. Workers entering the nest will track the dust into the nest and contaminate it. The problem is that it is most difficult if not impossible to track the nest.

Spiders

There are 35,000 species of spiders in the world. Most spiders that are a cause of concern to the public and which pest control experts are called upon to control are either large or have striking marking. The large spider is often thought to be a tarantula, and the coloured one the black widow. Only a few species of spiders reside in dwellings and a larger number stray or are carried into the houses.

The house spider

The house spider is so cosmopolitan and so widely distributed that it is difficult to trace its original homeland. The house spider selects its web sites at random. If the web does not yield prey, it is abandoned and another site is selected. Eventually the spider end up constructing webs where food is most available.

Control

It should be recognised that spiders are predators and require prey to survive. However spiders stray into dwellings and other indoor habitats. In windows and outdoor dwellings, spiders frequently construct webs as insect prey may be attracted by the light or brought in by the air flow. The removal of debris, lumber piles, and materials may reduce the presence of some species. Care needs to be taken when using clothing, tents, sleeping bags, and other items left unused for long periods in areas where spiders are common. Improved storage, use of air tight boxes and bags, elevation of materials off the ground, discarding unwanted items, and periodically sweeping or vacuuming under furniture and behind mirrors and pictures are all helpful control measures. Thick leather gloves should be worn when cleaning areas infested with spiders.

  Spiders are easily susceptible to most modern insecticides. One consideration which is important when web building spiders are being treated is their habit of recycling silk. They chew up the old web and consume the silk. They also have powerful digestive juices which dissolve the silk. This means that a dust formulation lightly applied to the web can be quite effective. Dust formulations are best directed against web building spiders and to entry cracks and crevices for spiders entering from outside of the structure. Space sprays are useful for spider problems in confined areas when there is no hazard to people using the structures. Residual sprays are usually applied to infested windows, corners, doorframes, roofs, and storage areas.

  Dust formulations for spiders include products containing bendiocarb, diazinon, malathion and pyrethrum. Space sprays are DDVP, pyrethrum, and resmethrin. Residual formulations include those based on bendiocarb, bromine, chloropyrifos, DDVP diazinon, malathion, propetamphos, propoxur, pyrethrum, resmethrin, and runnel. Since all the materials are effective, control depends on using a formulation that is effective against a spider species, or group that gives the best result based on the habits of the spider group.

Bed bug

This pest has plagued man since the dawn of civilization. It is believed that the bed bug originally was associated with bats living in caves in the Middle East. It was in the caves that these parasites became associated with man.

  Although this creature draws no line between the rich and the poor, its presence is more evident in the quarters of the impoverished, owing to conditions more favourable for its growth. Escaping through windows, they pass along walls water pipes, or gutters and thus gain entrance into adjoining houses. The bed bug is distributed readily in a laundry and on clothes and baggage of individuals who have visited infested areas.This pest is disseminated primarily from one house to another by stowing away in furniture and bedding that is being moved.

  These creatures are very wary and cautious, and their hiding place taxes the patience and ingenuity of man. Infestations can be detected by the bloodstains on the walls or linen, and by the characteristic spots of excrement. In addition to their disgusting appearance, the bugs make a mess and they stink. The mess is due to their frequent excretion which causes brownish yellowish or black spots on the walls near the crevices where they hide. The dark marks are due to the presence of partly digested blood in their faeces to make way for a fresh meal.

  The bed bug plays an insignificant role in carrying disease to man. However they do cause nervous and digestive disorders in sensitive persons. The house in which bugs are tolerated will be a home of malnutrition, dirt and other causes of physical inferiority.

Control

DDT which was once considered the best control measure for bugs is today not effective. The bugs have become totally immune to this insecticide. No matter what insecticide is used, the pest control specialist must try and find their place of hiding. He must look for any place that offers darkness, isolation and protection.

  Spray of 1% malathion, 1% fenchlophos, 0.5% DDVP, and 0.5% synegised pyrethrins have given good results. Mattresses should be treated only at the seams and should not be soaked in spray. Mattresses should be allowed to dry and should be covered when used. Several residual sprays used as water emulsions and or oil-based solutions may be used away from beds: 0.5% diazinon 2%malathion, and 1% fenchlophos. Hand spray is usually adequate and spraying should be done early in the day so that the insecticide can dry before the room is used for sleeping. Lindane, malathion, pyrethrin or fenchlophos can be used to spray mattresses. Pyrethrum treatments need to be repeatedly given on account of its limited residual action. Care should be taken not to sleep on a freshly sprayed mattress. Treatment of infant crib and bedding should be avoided.

Mosquitoes

Mosquitoes received very little attention until it was found that they were the cause for malaria and other disease. It was then that a study was conducted, and it has been found that there are 1,700 species of these insects in the world. While the mosquito is found abundantly in the tropical region, there are traces of them even in the Arctic region. Not all mosquitoes are blood suckers, and most of them are attracted to light. Hence light traps are used in order to obtain information about them. Only the females suck blood. The male feeds on pollen and nectar.

  The vast majority of them prefer water but some live in salt marshes and brackish water. Still others are happiest in water contaminated with sewage. Species that breed near houses and consistently enter houses are called domestic mosquitoes. There are two main types of mosquitoes - culicine and anopheline . The culicine type are painful biters and capable of transmitting certain diseases found in tropical areas such as yellow fever, filariasis and dengue fever. The anopheline group are capable of transmitting malaria.

  By and large, the mosquito constitutes a hazardous pest in the house. Many species inflict painful bites and some species do so at night. Scratching the itching bite often sets up secondary complications.

Control

Various methods for the control of mosquitoes have been developed. The ideal plan calls for a complete survey of the district, the mapping of all breeding places, and the identification of the species. This is necessary in order to determine the kind of mosquitoes and their breeding habits. Control consists essentially of destroying the larvae and their breeding places. Tin cans and all objects that hold water are eliminated and the rain barrels and cisterns are treated periodically. Draining provides permanent control and is used to eliminate small pools, swamps and marshy areas; ditches, and creeks are cleaned up so that water flows evenly and does not back up. Areas of water that cannot be eliminated by draining or leveling are sprayed or dusted.

  Prevention of bites is an essential feature in the prevention of mosquito borne diseases. All buildings should be screened to prevent entry of these insects.

Where there are no screens sleeping nets should be used. A mixture of indalone, Rutgers 612 and dimethylphthalate is a good general repellent. Aerosol bombs containing pyrethrum, rotenone or DDT are

used to kill mosquitoes in small areas. DDT is used to spray wells and screens, and is effective for long periods, but kills slowly, and should be used carefully. The aedes and culex remain in dark portions of the building and bite during the day. Spraying will destroy them and prevent the spread of dengue and filariasis (Fig. 16.2). Several types of small fish like Fundulus and Gambusia are useful in controlling mosquitoes and are often introduced into ponds and other breeding places.

Mosquito bite prevention

• - Stay in the breeze.The mosquito can fly only eight m.p.h., so it doesn't take much to waft her away
• - Wear long, loose-fitting garb to keep the mosquito from biting through to skin. Earth hues disguise us in the woods; green is best, brown rates second. White masks your silhouette in the open. Blue is worst; Mosquito mistakes it for a flowering plant from which she draws sustaining juices. Red flags her in also, as well as other insects
• - Keep a section of yard open to sun and breeze
• - Make a fire to create a dense, cool, low-hanging smoke. When smoke hangs around, the mosquitoes don't. This should not disturb the patients
• - Brush them off. Our most common mosquitoes take several seconds after landing to bite

Rats

Rats, mice and squirrels are from the same family -the Rodents. This group of animals is distinguished by their teeth – large and chisel-like front teeth. They use these teeth to gnaw through any kind of hard matter - wood and cement walls. There are many kinds of rats in the world, but only two kinds of rats the pest control man deals with-the Norway rat and the roof rat. The Norway rat is so called because it is believed that they originated in Norway. They are larger, and have larger droppings than the roof rat.

  Roof rats also known as black or ship rat prefer warmer climate and upper floors of buildings. The Norway rat prefers basements and often burrows around water sewers, docks or wharfs. Rodents urinate and leave droppings on the food they eat. Their hair also drops in these foodstuffs. Hence humans should not consume food contaminated by these creatures.

  In order to control rats the service man must be able to predict:

1. Where the rat will be
2. When the rat will be there
3. What the rats will eat
4. How the rats react to strange items of food.

  Rats are designed for darkness, and hence are active only at night. If rats are visible during the day, it means that the place is infested with rats. The rats depend largely on their sense of smell and touch. They are suspicious by nature and do not touch or go near anything unfamiliar to them. During inspection if a rat trail is found, then it is very possible that the rat will come back again to the same area.

  Rats eat the same kind of food that we do and prefer fresh clean food. They eat large amounts of the food that they like. Any new food is carefully examined by them and nibbled. If they do not like it they will not touch it again. If they do, they will come back only after a period of time. Thus rats are very clever to ignore poisoned food, however attractive the food may be. In the case of poisoned food, if a few rats die after eating the food, other rats in the colony will not come anywhere near to it.

The house mouse

Like the rat the house mouse is most active during the night, but unlike rats the house mouse is not suspicious; rather, it is curious.

  The control technique for the house mouse is very different from rats. Hence the service person must know which of the two he is treating.

  One common technique is baiting – combination of food with toxic material. In order that this is effective, the serviceman must know what the rodents are eating and where they are getting their food and water.

  Another is traps. These will be effective only if they are placed in the rodents’ route or trail. Elimination of rodent nesting place or hide-outs is another method of control. The rodents may be nesting outside the building, but enter the building in search of food. We must find out the point of entry. Rodents leave clues or signs in their path. Correct reading of these signs will enable these servicemen to determine the kind of rodents, sources of food and water, where the trails are located where they are entering the building and where they are nesting. In order to keep their teeth in good condition, the rodents gnaw on hard surfaces. This is a big tell tale mark to know that rodents are around. Rodents also like to touch or be in contact with walls and other surfaces as they travel. This habit of theirs leaves rub marks on the walls.

  Once a rat is killed it should be picked up with a pair of tongs gloved hands or a stick. If the fleas should bite the serviceman, it will transmit the disease to him. All dead rats should be buried.

Making buildings rodent-proof

1. Place a curtain wall or barrier of metal, or concrete around and below the foundation of buildings
2. Wooden floors should be replaced with concrete
3. Close all vents around pipes with brick stone or cement
4. Protect ventilator grills and low windows with galvanised steel mesh
5. Ensure that the clearance between the door and sill is not more than 3/8 “
6. Flashcellardoorswith24gaugegalvanisedsheetiron
7. A metal cover with small perforations should be cemented over the drain pipes in the floors and openings around the drain
8. Circular rat guards should be placed around vertical pipes and wires to prevent rats from climbing up

Control

Mechanical control

Snap traps: trapping is done when the use of poisons is dangerous. Traps can be used again and again. The bait should be tied securely to the trigger. This prevents the rodent from nibbling the bait without setting off the trigger. The bait may be food or cotton. The rat uses the cotton for nesting.

  Electromagnetic or ultra sound devices: electromagnetic devices work on the principle that a magnetic field produces a barrier which has a stunning effect on the rodents. The ultrasonic device works on the principle that certain high frequencies and amplitudes of sound are irritating. Ultrasonic sounds are directional and rodents seek shelter behind solid objects. In such cases there should be alternate use of baits and traps in these shadow zones.

Chemical control

ANTU:this kills rats by causing acute lung dropsy and an accumulation of fluid in the chest cavity. Death usually occurs within 12 – 48 hours. ANTU should be thoroughly mixed into the bait

Arsenic:this chemical is odourless and tasteless, and is therefore easily taken by the rat when mixed with food. However, on account of the very same properties, care should be taken that it is not accidentally consumed by humans.

Barium carbonate:This too is tasteless and odourless, and inexpensive. The toxicity of this poison is not very consistent. Some rats die after consuming very little of it, while others are no affected.

Phosphorous paste:This material is spread between two slices of bread in the form of a sandwich. Since phosphorous glows in the dark, one need to be careful. It dissolves easily in fats, and should therefore be used with greasy baits.

Fluoroacetamide:This is used for the control of sewer rats, as it can be used in water baits.

Strychnine:This is extremely poisonous and characterized with very rapid action. However it has a bitter taste and is not generally taken by rats.

Zinc phosphide:This too is a quick killing rodenticide. However it has a strong garlic – like odour, which alerts rats when mixed in food.

Termites

Termites are insects that cause serious damage to wood and paper. They actually eat wood as food, and like ants, live in colonies.

  There are three types of termites – the subterranean, the damp wood and the dry wood termites. The subterranean termite lives in the ground which provides the dampness required for it to stay alive. The damp wood termite needs a lot of moisture to survive, but does not need to return to the ground. It can stay in the wood which is close to the ground or near a leaking roof. The dry roof termite is often found living in desert areas. They do not need water or moisture to survive and can nest in dry seasoned wood.

Post construction termite treatment

White ants attack a building from their colonies under its floor or from outside or both. Any treatment given should be such that it prevents future re-infestation through the foundation. This is achieved by four technical operations.

Structural alterations: This includes any structural operation which renders a structure less susceptible to termite attack or which renders the immediate surroundings of a structure less favourable to termites.

Soil treatment: chemicals are applied to the soil immediately adjacent to or under a structure for the purpose of eliminating existing infestations and creating an insecticidal barrier.

Foundation treatment: this involves application of chemicals to any type of foundation for preventing access to termites.

Wood treatment: chemicals are applied to wooden members of the structures to render them resistant to termites.

Pre construction termite treatment

• - Treatment to the bottom of trenches upto 30cm height
• - Treatment to the sides of the foundation after the backfilling is done
• - Treatment to the wall and floor joints, and under the floors
• - Treatment to the external perimeter of the building upto a depth of 30cm.

Student exercise

Answer the following