Fixed Action Pattern
"(groom): to clean and condition; to make neat or attractive" [Merriam-Webster]
Pictures from Zoo Report NO. 22 and Kilauea Point National Wildlife Refuge.
Grooming is one of the most common animal behaviours. There are two kinds of grooming: grooming oneself and grooming others. When an animal grooms itself, it is doing it to keep himself clean. However when an animal grooms another of its kind, it is showing its love towards the groomed one. In this picture, the mother is showing that she cares about her child by grooming it. The tiger is grooming himself, so he is cleaning himself.