A robot is provided, the robot comprising a body carrying a first drive arrangement, a second drive arrangement and a stabiliser. The robot further comprises actuators operable to cause relative movement of the first drive arrangement, the second drive arrangement and the stabiliser, and to drive the first and the second drive arrangements. The robot is arrangeable in first, second and third configurations each having static stability. In the first configuration, the stabiliser and the first drive arrangement are arranged to contact the ground. In the second configuration, the stabiliser and the second drive arrangement are arranged to contact the ground. In the third configuration, the first and the second drive arrangements are arranged to contact the ground. No other ground contacting point is involved in conferring said static stability in said configurations.