The Control of Ants

There are two types of ant common in this country, the Black Garden Ant, which is dark brown in colour, and Pharoah's Ant, which is reddish yellow in colour.

The Black Garden Ant (Lasius Niger)

The Common black ant (worker measuring 3.4-5mm long and dark brown-black in colour, queen 15mm long and mid-brown) is an active insect, nesting outside in grass and walls and under paving.  It will forage widely in search of food, which is how it comes to enter domestic premises.

Foraging worker ants cause a nuisance as they travel widely in search of food, following well-defined trails and clustering around the food source.  They are particularly attracted by sugar, syrup and jam or other similar sweet foods.

In gardens, their excavations around plant roots make the soil excessively dry.  They will also cultivate greenfly, themselves pests, in order to obtain the sugary honeydew secretions that these aphids produce.  On the other hand they can be beneficial as predators of other insects and general scavengers.  They are obviously an unpleasant sight and may damage food used for human consumption.

The gregarious habits of these ants have resulted in the development of a caste system, whereby individuals are responsible for specialised duties within the community.  There are: workers (sterile females); fertile males; and queens (fertiles females).  The worker ants build and extend the nest, look after larval forms and forage for food, whereby they become pests.  The queens do none of these duties, but remain almost exclusively within the nest.  Mating amongst sexual individuals takes place on the wind.  These spectacular swarms involve large numbers of ants.

The actual swarms only persist for 2-3 hours.  After mating the males perish but the females shed their wings and dig a cell in the cell where they stay over winter.  The eggs are laid in late spring and the white legless larvae hatch 3-4 weeks later.  The larvae are fed on secretions from the queen's salivary glands until fully grown, when they will pupate, forming the well-known ant eggs.  From these pupae emerge the first brood of worker ants.  These workers take over foraging duties and tend subsequent broods.  The sexual forms are not produced until later.  The entire cycle takes about 2 months to complete.  Under favourable conditions a nest may persist for several years.

The Pharoah's Ant (Monomorium Pharaonis)

The Pharoah's ant (workers 1.5-2mm long and yellow-brown in colour, males 3mm long and black in colour and are winged but do not fly, Queens are 3.6-5mm long in size and dark red in colour, also winged but do not fly, wings are lost soon after mating) originated in North Africa and spread along international trade routes.  Their need for warm humid conditions means that in temperate lands they are confined to buildings.  Infestations can be found in a wide variety of locations including residential blocks, zoos and ships.

Infestations spread through buildings by way of service ducts.  The ants can survive low temperatures for prolonged periods with the workers continuing to forage for food.  Infestations in buildings are relatively unaffected by the seasons although may be encouraged when heating systems are switched on during the winter.

Worker ants are a nuisance as they forage widely for food and water following scent marked trails.  They will feed on meat, cheese, fats, sugar, honey, jam, chocolate etc.

Pharaoh's ants pose a risk to health.  Pathogenic organisms may be transmitted mechanically as the ants feed in unhygienic places including drains and refuse bins.

Pharoah's ants are social insects and live in colonies.  These colonies consist of:  workers (sterile females), fertile males and queens (fertile females).  There are usually many queens in a colony (multi-queen colonies) and they co-exist amicably.  The queens can be replaced so colonies will exist indefinitely.  New colonies may be encouraged by disturbing nests.  Worker ants carry larval stages to a new nest site from which they can rear queens and males.

Flying swarms are never seen, mating taking place in the nests and interstices of buildings.  Each queen produces up to 350 eggs.  These hatch in about a week to legless larvae which are fed by the queens and tended by the workers.  The whole cycle from egg laying to adult takes about 5 1/2 weeks depending on temperature.

Control

There are numerous brands of insecticide on the market, available in most chemist shops, in aerosol form, which can effectively control both types of ant.  One type specifically for 'crawling insects' contains a lacquer which will kill any ants which crawl over it and remains effective for 3 to 4 weeks.  This can be sprayed wherever garden ants gain access to a dwelling, e.g. across door steps, around window and ventilator openings and tiny fractures in brickwork; and along skirtings, behind hot water pipes and heating appliances where the indoor ant is likely to live.  This particular type of insecticide should not be used where open food is present and should not be inhaled.

Where pests are found either inside the dwelling or in the garden, a normal fly control aerosol will kill all the insects, if this is not available, boiling water can be used in an emergency.  The fly control aerosol can also be used against flying ants.  Some manufacturers produce a liquid in tube form which is carried back by the ant to its nest and has proved to be reasonably effective in killing the queen.  You must, however, spray with a residual insecticide within 5 days of using the liquid, otherwise the working ants may hatch another queen to keep the nest alive.

Manufacturers of all insecticides produce specific instructions as to their use and these are normally printed on the container (aerosol or tube).  These instructions should be strictly followed.  An effective treatment is the use of a powder which contains Bendiocarb.

Normal good housekeeping hygiene helps to minimise the ant problem and in particular, all sweet foods and jam should be stored in air tight containers and meat, cheese and fats in cool conditions, preferably a refrigerator.  Scraps of food should be properly disposed of by burning, or placed in the refuse receptacle outside the dwelling.

Treatment

North Shropshire District Council does offer a service for the treatment of ants (inside house only).

For people receiving the following benefits:

• Income Support
• Income Based Job Seekers Allowance
• Working Tax Credit
• Housing Benefit
• Council Tax Benefit
• Pension Credit (Guarantee Element)

the charge is £20.00 (2008/09).

If you do not receive any of the above benefits, the charge is £40.00 (2008/09).

Details of private pest control companies are available in the Yellow Pages.

Related Documents

The Control of Ants