There are estimated to be 400 million dogs in the world.

More than 800 dog breeds are recognized by various kennel clubs worldwide.

Cats have free-floating clavicle bones (collarbone),  which allows them to pass their body through any space into which they can fit their heads.

A group of cats is referred to as a clowder, a male cat is called a tom (or a gib, if neutered), and a female is called a queen.