How did dogs become our pets? It began a very long time ago. Dogs came from wolves.

Dogs have lived with people for at least 14,000 years. They have helped us since ancient times.

Dogs belong to a family of animals called canids. Wolves, coyotes, foxes and jackals are canids too.

People have used dogs for hunting, guarding and herding. Guide dogs help people who are blind get around.

Search and rescue dogs use their noses to find missing people. They find people after disasters too.

A dog's smell is far, far stronger than ours. Dogs learn about the world with their noses and eyes. They can also hear very high sounds that people cannot hear.

A puppy is born with its eyes closed. It cannot see at first. Its eyes open at about one to two weeks old.

Dogs mostly cool off by panting, not by sweating. A dog has some sweat glands in its paw pads. They do little to cool it down.

Ask the owner if it is okay to pet a dog. If it is, let the dog sniff your closed hand. Leave a dog alone when it eats, sleeps or chews.

Words to know

• canids: dog family
• herding: moving sheep
• rescue: save people
• sniff: smell