Which of the following is NOT a characteristic of insects?

The correct answer reflects the fact that not all insect species possess wings. While many insects do have wings, including butterflies, bees, and flies, there are numerous species that are wingless, such as ants, termites, and certain types of beetles. This characteristic does not apply universally across the insect classification.

Insects fundamentally have three main body parts—head, thorax, and abdomen—that define their anatomical structure. They also possess an open circulatory system, which is characteristic of most arthropods, allowing for the circulation of hemolymph throughout their bodies. Additionally, all insects do have three pairs of legs, which is a defining trait of the class Insecta. Thus, the presence of wings on all species is the notable exception in the characteristics of insects.