14th March 2012
Dear Mr Warren,
Burrows vary from temporary structures of simple design to more permanent underground networks that may be inhabited for several generations. They vary in structure from blind burrows with a single opening to extensive systems with several openings. Some animals live permanently underground, and their burrows have no obvious large openings to the surface. Burrows may be shared by a number of species, and abandoned burrows may be used by other species. Animals with limbs usually excavate their burrows by using their legs, but many burrowing animals are limbless and the mechanism of progression is not always obvious.
Regards,
The Abministrator