Most North American rabbits don't dig their own burrows, so they use whatever's out there: burrows dug by badgers, woodchucks, kit foxes, etc. Obviously, there's enormous variability in the dimensions of those burrows. Burrows dug by the Pygmy Rabbit, arguably the only species to dig its own burrows, are about 10-15 feet long, roughly 3 feet deep at the bottom, and 3-5 inches wide at the mouth. This species also frequently uses other animals' burrows.
