The cat (or domestic cat, house cat) is a small carnivorous mammal that is often valued by humans for its companionship and its ability to hunt vermin. It has been associated with humans for at least 9,500 years. A skilled predator, the cat is known to hunt over 1,000 species for food. The cat is intelligent and can be trained to obey simple commands. Individual cats have also been known to learn to manipulate simple mechanisms. Cats use a variety of vocalizations and types of body language for communication, including mewing ("meow" or "miaow"), purring, hissing, growling, squeaking, chirping, clicking, and grunting.