A group of adult cats is called a clowder, and a group of kittens born together is called a kindle.

The word clowder comes from the Middle English word clodder, which meant a thick mass or a clot. This term was recorded in 1486 in a book called The Book of Saint Albans. This book listed many specific names for groups of animals. The word kindle comes from the Middle English word kindelen, which means to give birth to young.Domestic cats are facultatively social. This means they can choose to live alone or in groups depending on their environment. Dr. Penny Bernstein at Kent State University studied how cats organize themselves. She found that cats living near farms or in cities often form clowders because there is enough food for everyone.These groups are usually led by females. Related females in a clowder often help each other raise their young. Biologist Dr. David Macdonald observed this behavior in 1983. He saw that different mothers in a group would sometimes nurse and groom the same kittens. This is called alloparenting.The size of a clowder depends on the food and shelter available in the area. In Rome, Italy, some protected cat colonies have up to 30 cats. Cats in these groups even have preferred associates. This means they have specific friends they spend more time with. This social flexibility helped the ancestors of cats live near humans starting about 10,000 years ago.