insects and arachnids Highly diversified grouping of all animal invertebrates, (over 1 million species of insects and 50,000 species of arachnids); they are more numerous than all other animal or plant species.
examples of insects Insects: invertebrates with bodies divided into three parts; they usually have three pairs of legs, two pairs of wings and antennae.
examples of arachnids Arachnids: invertebrates usually with four pairs of legs and two pairs of appendages attached to their heads.
butterfly Adult insect having two pairs of wings and three pairs of legs; it emerges after the first three stages of metamorphosis: the egg, the caterpillar and the chrysalis.