Horses look after their skin and coat by rubbing themselves against objects, rolling and scratching. Where possible, they seek out wallows and then rub off the encrusted mud by rolling. This type of behaviour is particularly frequent if the horse is infested by external parasites or while moulting.

Body parts such as the withers and croup, which the horse cannot reach by itself, are groomed by other members of the herd; this behaviour is known as social or mutual grooming. Through facial expression and by nibbling the withers and croup of fellow group members, horses can invite them to engage in mutual grooming, standing side by side with heads on each other’s backs or flanks. Social facilitation plays an important part here, as it does in other forms of behaviour (panic and flight). This grooming behaviour is an important medium for social contact and is inborn. Vigorous scratching of a horse’s croup can induce the grooming reflex, in which the horse extends his upper lip or makes rhythmic nibbling movements in vacuo.