Hobbies And Interests
The Number of Legs is Important
Adult insects have six legs compared to the eight or more of most other arthropods.
Head, Thorax and Abdomen
Adult insects have a head, a thorax and a multi-segmented abdomen, dividing the body into three distinct parts. Most other arthropods appear to have two body parts.
Wings
Most adult insects have four wings attached to the thorax. Flies (Order: Diptera) have two functional wings with the second pair modified into small, clublike appendages called halters.
No Wings
Not all insects have wings. Some insects, including fleas, lice and some worker ants, have evolved to be wingless. Other ants and termites lose their wings after swarming and mating.
Sensory Organs
Antennae on the front of the insect's face act as tactile and smell organs. Simple eyes (ocelli) and compound eyes are the visual organs for adults. The compound eyes are on the side of the head while three ocelli are located in a triangle somewhere between the front and the top of the head.
Diversity and Similarity
Insects are the largest class of animals.They have great diversity. But, close examination will show three body sections, six legs, compound and simple eyes, two antennae, and, usually, four wings.