Ants are common social insects that live in structured communities – colonies. Each colony has a precise structure and each member has specific task assigned. From about 22.000 estimated species 12.500 of them have been identified and only 450 are considered as pests, and therefore remain are our point of focus. Those ants belong to the family Formicidae in the Order Hymenoptera. Ants are considered the most important household pests in Malaysia, after mosquitoes and cockroaches.
General biology and behaviour
The body of an ant consist of three parts: head with eyes and antennae, thorax with three pairs of legs and two pairs of wings, and abdomen. Depending on the species, one or two nodes are placed between the thorax and abdomen. Ants are often mistaken with termites, because they lookalike. However, termites do not have these nodes between the thorax and abdomen. What is more, unlike termites they have bigger heads, elbowed antennas and strong jaws. Ants and termites can be also differentiated by the size and shape of wings.
The lifecycle of ants is based on 4 stages of the development: egg → larva → pupa → adult. Eggs are of microscopic size and white colour. Next stage in the development is larva – larvae are legless and fragile and need to be protected/taken care of by worker ants. Pupae are similar to adults, but they are immobile, soft and of a white colour. The last stage of the development is an adult ant. Caste system is remained in colonies and we can distinguish two types of ants: 1. Reproductive – queen(s) and males and 2. Non-reproductive – workers and immature (ants on earlier stages of development).
Colonies are structured and the division of labour is crucial for the colony to survive. The queen is responsible for laying eggs. Workers are the most common ants seen by people and have a wide range of tasks. They gather and storage food, bring it to immature and defend the nest and clean it from the remnants.
The queen is the most important ant and her function is to lay thousands of eggs to ensure the continuity of the colony. Queens mate only once and then are able to reproduce throughout the while life. Therefore males are only needed to mate the queen and most of them die after mating.
Medical and economic importance
Ants are unwanted and irritating to people. Many customers are discouraged to dine in a restaurant where they have noticed ants. Some of the species are a threat to the human health by spreading pathogenic organisms to people. Pharaoh ants are known to contaminate surgical instruments in hospital and feed on wounds of patients. Other can carry (e.g. fire ants) stings that cause pustules and blisters. Carpenter ants are able to nest inside wood structures and make damage to the construction of houses and other buildings.
Although ants have a lot in common with termites, ant control is much more difficult. Locating ants’ colony and eliminating it the nest is the most effective solution, thought extremely tough as well. Control solutions range from non-repellent residual insecticides to perimeter treatment and insecticide. Baiting system seems to be the best method of eliminating ants. Throughtophallaxis ants will transfer contaminated food among other members of the colony, systematically bringing it to the nest and feeding the queen. However, baiting may fail due to changing nutrition needs of ants. A colony with lot of immature will prefer to gather food based protein, rather than carbohydrate.
As in every case in pest control, prevention is the best cure. Sanitation and regular cleaning will keep ants away from our homes. It is very important not to leave any food exposed in the kitchen area, garbage can and sink. Additional measures include leaving sachets of sage, bay or cinnamon sticks inside cupboards. That will repel ants and leave a pleasant smell as well.