Insects or Bugs

Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely distributed grouping within the Phylum Arthropoda. The study of insects is called entomology.

Insects comprise the most diverse group of animals on earth, with over 800,000 species described—more than all other animals groups combined. Insects may be found in nearly all environments on the planet, although only a small number of species have adapted to any kind of life in the oceans. There are approximately 5,000 dragonfly species, 20,000 grasshopper, 170,000 butterfly, 120,000 fly, 82,000 true bug, 350,000 beetle, and 110,000 bee and ant species.

A few smaller groups with similar body plans, such as springtails (Collembola), are united with the insects as the Subphylum Hexapoda. The true insects (Class Insecta) are distinguished from other arthropods in part by having ectognathous, or exposed, mouthparts and by having eleven abdominal segments. Most species, but by no means all, have wings as adults. Terrestrial arthropods such as centipedes, millipedes, scorpions and spiders are often confused with insects due to the fact that both have similar body structures.