If this use of alligator dens doesn’t impress as a form of protection, then think of alligator babies. That’s right: cute little alligator babies, which easily fit on the palm of an average adult human hand when newly hatched. Only later do they grow up to become monsters—much like how human children eventually turn into teenagers. Despite being so adorable, nearly everything bigger than a baby alligator—including other alligators—regards it as an appetizer. Hence these little tykes need defending, which is partially provided by their overprotective mothers, but also by dens. Alligator mothers stay with their offspring for as long as two years after they hatch, and if dens are nearby, they will use these not only as places with plenty of fresh water (which baby alligators need), but also for hiding the kids from trouble.
From: The Evolution Underground by Anthony J. Martin