It is traditional in many areas to place rings in bulls' noses to help control them. The ring is usually made of copper, and is inserted through a small hole cut in the septum of the nose. It is used by attaching a lead rope either directly to it or running through it from a head collar, or for more difficult bulls, a bull pole (or bull staff) may be used. This is a rigid pole about 1 metre (3 ft) long with a clip at one end; this attaches to the ring and allows the bull both to be led and to be held away from his handler.
An aggressive bull may be kept confined in a bull pen: a robustly-constructed shelter and pen, often with an arrangement to allow the bull to be fed without entering the pen. If an aggressive bull is allowed to graze outside, additional precautions may be needed to help avoid his harming people. One method is a bull mask, which either covers the bull's eyes completely, or restricts his vision to the ground immediately in front of him, so he cannot see his potential victim. Another method is to attach a length of chain to the bull's nose-ring, so that if he ducks his head to charge, he steps on the chain and is brought up short. Alternatively, the bull may be hobbled, or chained by his ring or by a collar to a solid object such as a ring concreted into the ground.
In larger pastures, particularly where a bull is kept with other cattle, the animals may simply be fed from a pickup truck or tractor, the vehicle itself providing some protection for the humans involved. Generally, bulls kept with cows tend to be less aggressive than those kept alone. In herd situations, cows with young calves are often more dangerous to humans. In the off season, multiple bulls may be kept together in a "bachelor herd".