Dogs are mammals. They have long or short fur, ears, legs and a tail. They come in so many different colors, shapes, and sizes. There are about 340 breeds of dogs.

Scientists believe that dogs were first domesticated over 10,000 years ago. To domesticate means to tame. They were probably the first animal to be tamed by humans.

Since then, dogs have been used in a number of different ways. They have herded livestock. They have helped protect properties. Dogs have also helped do police work and rescue people in certain situations. Some dogs have guided people who cannot see. And they have also become our friends. Many people today have dogs as pets. They enjoy the companionship dogs give.

One of the main reasons why dogs have been so useful to humans is because they are able to communicate in different ways. Dogs can growl and bark loudly when they sense danger. They can wag their tails with excitement when they are happy. They can use their bodies and voices to communicate a message.