How many types of animals live underground?

There are numerous types of animals that live underground, including mammals, reptiles, amphibians, insects, and some birds. Common examples include moles, gophers, rabbits, and various burrowing rodents. Additionally, many insects, such as ants and termites, create complex underground colonies. Overall, the diversity of underground-dwelling animals is vast, with adaptations that allow them to thrive in subterranean environments.