Ants are found in all regions of the world even dry deserts and the cold Arctic. There are about 12,000 species of ants worldwide and they are the most common pest in households. The body of an ant can be divided into three distinct regions: head, thorax, and abdomen. The abdomen consists of the narrow constriction (waist or petiole). The waist can be made up of one or two small segments (nodes) and this is an important identifying feature, based on which ants are broadly grouped as one-node and two-node ants. Ants have chewing mouthparts and a pair of antennae used for smell and touch.