Which of the following is an example of a social insect?

Social insects are characterized by their colonies or communities where they exhibit complex social behaviors, such as division of labor, cooperative care of the young, and the ability to communicate with one another. Ants are a prime example of social insects because they live in highly structured colonies consisting of various castes, such as workers, soldiers, and queens, each performing specific roles essential for the survival and efficiency of the community.

In contrast, spiders are primarily solitary creatures, as they do not form colonies and usually live and hunt alone. Butterflies and moths also do not exhibit social behavior to the extent seen in ants; they tend to be solitary or engage only in mating interactions rather than forming cooperative living structures. The social structures and behaviors observed in ants are a key defining characteristic that distinguishes them from the other options listed, thereby making them the correct answer.