Characteristics :

  • Body in three main sections: head, thorax or trunk, and abdomen; the thorax has three sections, or segments, through they may not be obvious; the abdomen has up to ten obvious segments
  • Body covered with an external skeleton, called an exoskeleton; some have a flexible exoskeleton and in some the exoskeleton is hard
  • usually have two eyes with many lenses, called compound eyes, and some have three additional eyes with only one lens each, called simple eyes
  • One pair of antennae, or feelers, on the head
  • Three pairs of walking legs, all attached to the thorax an dusually having one or two claws at the end
  • Many have two pairs of wings attached to the thorax
  • Breathe by a system of tubes, rather than lungs or gills
  • Most undergo changes in appearance and behavior, or metamorphosis, as part of their life cycle; some undergo incomplete metamorphosis in which the immature form looks similar to the adult, others undergo complete metamorphosis in which the immature form looks different from the adult
  • Kingdom: Animalia
    • ​​Phylum: Mandibulata
      • Class: Insecta
        • Order:Anoplura (sucking lice), Coleptera (beetles), Dermaptera (earwigs), Diptera (flies, mosquitoes), Ephemeroptera (mayflies), Hemiptera (treu bugs: assassin bug, chinch bug), Hymenoptera (ants, bees, wasps), Isoptera (termites), Lepidoptera (butterflies, moths), Megaloptera (dobsonflies, alderflies), Odonata (damselflies, dragonflies), Orthoptera (crickets, grasshopers, mantids, roaches), Plecoptera (stoneflies), Siphonaptera (fleas), Trichoptera (caddisfiles)

Student Challenge

  • Take photographs of, or sketch, five different types of insects. Try to find representatives from five different orders as shown in the taxonomy section above. 
  • What do these five insects have in common?
  • How are they different?
  • How do the adaptations seen in the different orders help each of them survive? Interview your County Extension Agent, a college professor of biology, or an entomologist to learn how these insects affect the ecology of your area. Develop a brochure using your photographs and the infromation you have learned to teach others in your community about these insects. Contact number for your County Extension Service can be found at