Definition of Insects

Insects are the most numerous life form on the planet (in terms of number of species). Approximately seven out of every eight living species are insects. Insects show a number of characteristics, the three by which they are most easily recognised are:-

1. Three body parts
   • Head
   • Thorax
   • Abdomen
2. Three pairs of legs
3. Two pairs of wings

A photograph of a Red Admiral butterfly (Vanessa atalanta). Butterflies are some of the most well-known insects.

Related terms

• Abdomen
• Apterygota
• Blattodea
• Coleoptera
• Collembola
• Crane fly
• Dermaptera
• Diplura
• Diptera
• Endopterygota
• Exopterygota
• Head
• Hymenoptera
• Invertebrate
• Johnston's organ
• Minibeast
• Odonata
• Thorax
• Uniramia

Related groups of terms

• Arthropod Classes
• Broad groups of insects
• Insect Orders
• Insect life cycles

Related pages on this web site

• Insects & Man
• Key to adult insects
• The Insects - Class Insecta

See other words beginning with I