Burrows are the most common type of homes for small mammals. Mole rats are among the best burrowers. The Russian mole rat, digging with its teeth, can shift 50 times its own weight of soil in about 20 minutes. Moles can dig a 2 m (61/2 ft) long tunnel in about 12 minutes. At this rate it would take a mole only four years to dig its way from London to Paris.