Which insects have a "cast system"?

Insects that exhibit a caste system are characterized by a social structure in which individuals specialize in different roles within their colony. This system is most prominently seen in social insects like ants, termites, and bees.

These insects organize themselves into distinct castes, typically including workers, soldiers, and reproductive individuals. Each caste has specific responsibilities that contribute to the overall functioning and survival of the colony. For instance, worker ants and bees are responsible for foraging, caring for the young, and maintaining the nest, while the queen focuses on reproduction. In termites, the differentiation among castes also plays a crucial role in building and maintaining their complex colonies.

The other groups mentioned, such as flies, beetles, grasshoppers, crickets, butterflies, and moths, do not exhibit this type of social organization. Instead, many of them lead solitary lifestyles or have simpler forms of social interaction that do not involve the specialized roles seen in caste systems. Therefore, the correct response highlights the unique social structure of ants, termites, and bees, which is pivotal to their collective survival and success as a species.