What group does not classify as an insect?

The sowbug does not classify as an insect because it belongs to the group known as crustaceans, which are part of the class Malacostraca. Sowbugs have a hard exoskeleton, multiple pairs of legs, and are primarily aquatic or semi-aquatic in nature. They are more closely related to crabs and shrimp than they are to insects, which belong to the class Insecta.

In contrast, centipedes, ants, and mites are all classified as insects or insect-like organisms. Centipedes are part of the class Chilopoda but are often discussed alongside insects due to their similar structure. Ants are social insects classified in the order Hymenoptera, and mites fall under the class Arachnida but share a common classification in pest control discussions. The key factor that distinguishes the sowbug from insects is its biological classification and the physiological differences that arise from its aquatic ancestry.