Aardvarks are pig-sized mammals (up to 82 kg) that specialize in insectivory, especially in capturing and consuming termites. Their limbs are modified for digging into the very hard termite mounds found in African savannahs. The nails are actually somewhere between true nail and hoof in form. They are strongly constructed, shovel-like, and obviously adapted for digging. Aardvark skin is thick and sparsely haired. The thickness of the skin protects these animals from biting ants, and aardvarks may sleep in the ant nests they have recently excavated for feeding.