A cat's whiskers serve several important purposes. They are highly sensitive tactile hairs that help cats navigate their surroundings and detect changes in their environment. Whiskers help cats determine the size of openings or gaps, sense air currents, and judge whether they can fit through narrow spaces. They also provide information about their surroundings, helping cats avoid obstacles and hunt effectively in low light conditions. Additionally, a cat's whiskers can also indicate their mood or emotions, as they may be pulled back when the cat is frightened or agitated.