Insects are small terrestrial invertebrates that have an exoskeleton and six legs. They do not have an internal skeletal system, thus the need for an exoskeleton (hard outer shell). They are the largest animal group on earth. It is thought that they make up more than 90% of all animal species on earth.
The body of an insect has 3 sections: a head, a thorax, and an abdomen. Their two compound eyes and antennae are located on their heads. The wings (usually two pairs) and legs (3 sets of jointed legs) are located on the thorax. The abdomen of the insect houses their stomach, heart, and excretory system (which they use to get rid of waste). Stinging insects such as bees and wasps also have a stinger located on the abdomen.