Ants are social insects that live in colonies. About 10000 species of ants have been identified, but only about 40 species of them are considered as pests in the human environment. They are classified under the family Formicate in the order Hymenoptera. A household insect survey conducted in Malaysia revealed household ants as the most important household pests after mosquitoes and cockroaches. (Pesticide Control Division of Agriculture Malaysia, 2004)

Typical lifecycle of ants

• General Biology and Behavior

There are three body regions in an ant: head, thorax, and abdomen. The head consists of eye and antennae. On the thorax, there are three pairs of wings (in the reproductive stage only). Between the thorax and abdomen, there is/are one or two nodes (depending on species). Gaster, sting, and node(s) are components of the abdomen. A good understanding of the morphology of ants is essential for the correct identification of ants species.

• Medical and Economic Importance

Most household ants are nuisance pests. The sight or presence of ants in food and drink is irritating to many people. In addition, the swarming of ants which may occur within premises are quite disturbing too. Some other species are of medical importance (e.g: fire ants) because they carry stings that can cause pustules and blisters. On the other hand, ants are capable of being a mechanical vector of human disease too. As scavengers in kitchens and other food-handling areas, as well as garbage cans, dirty floors, etc, they have the potential to transmit pathogenic organisms to humans. In addition, the Pharaoh ants have been shown to cause contamination of surgical instruments and to feed on wounds of patients in hospitals.