Colonial bats are best defined as which of the following?

Colonial bats are defined by their tendency to live in large groups. This social structure differentiates them from other bat species, which may prefer solitary living arrangements. In a colonial setup, these bats often roost together, providing benefits such as increased warmth and protection from predators. Large colonies can also facilitate mating opportunities and enhance foraging efficiency within a shared habitat.

In contrast, solitary bats live independently and do not engage in the same social behaviors associated with colony living. The other options describe characteristics that do not specifically define colonial bats. While many bats exhibit nocturnal behavior, being nocturnal does not relate to their social structure. Similarly, although some bats inhabit caves, colonial bats can also roost in various other locations, such as trees or buildings. Therefore, the defining aspect of colonial bats is their grouping behavior, making living in large groups the correct choice.