Wolves also use different gestures to ask each other to play. When a wolf wants to play, it will approach another wolf and it will bow down with its front feet on the ground and its rear in the air with the tail wagging. It may also wipe its paw against its face. If the other wolf wants to play, it will approach the initiator, who may then stay in the crouched position or who may then bound away. The two will play fight or chase each other until they are tired. While wolves play, they may growl at each other playfully, let out loud, high-pitched dog-like barks, or gently bite and nip each other. Wolf pups are very playful, and adult wolves occasionally will play. During such relaxed situations, exceptions to the normal pack hierarchy often occur. For instance, during play, a dominant wolf may behave as though it were subservient to a lower-ranking wolf, and a subservient wolf may appear to be dominating a higher-ranking wolf.