They may not appreciate the extreme hazards posed by operating machines and may reach in or not stay away. Children may play on parked machines and fall off it or have it fall on them. Parked equipment should always be lowered to the ground. Extra tractor wheels leaning up against a wall should be secured to prevent them tipping over and crushing someone. Bulls, especially dairy bulls, can suddenly turn on someone and cause fatal injuries, and should never be trusted.
Stallions are also dangerous.
Boars can seriously rip and tear with their tusks. New mothers, such as cow or sows, will vigorously defend their young. Any animal being handled can easily pin a handler against a wall or fence, or step on hands or feet. Flowing or crusted grain in grain bins can lead to entrapment and suffocation. No one should enter a grain bin during unloading, as the downward flow of grain will pull a person under and entrap them.