Although some Aussies are born with naturally bobbed or partially bobbed (stubby) tails, the majority are born with full, long tails. Breeders have historically docked the tails when the puppies are born. In the United States and Canada, the standard calls for a natural bob or docked tail not to exceed four inches as a defining characteristic. Any natural tail length is permitted when showing in Europe, where cutting off a part of their tail has been banned in most countries, including the United Kingdom.