When we look at animals, we know that they are not humans. But how do our closest friends' dogs see us? Do they know that we are humans? Or do they actually think that we are just strange-looking dogs?
You may be surprised to learn that many kinds of animals do not notice such differences very much at all. For example, the cuckoo（布谷鸟）will lay its eggs in the nest of another bird. These birds will feed（喂食）the baby cuckoos, even though they look nothing like their real babies. This is because feeding little ones is quite natural for birds.
Other animals, it seems, will simply divide the world into animals they eat, and animals that eat them. When it comes to dogs, though, there is no simple answer to this question.
Sheepdogs leave their mothers when they are born. They grow up with sheep, and come to see them as their family. For this reason, they never attack（攻击）the sheep. Instead, they help protect them. They probably think the sheep are dogs too, but we can't be certain.
Similarly, if you raise a dog from birth, the way it sees the world will be different from a dog that grows up with other dogs. It will probably think it is the same kind of animal as you. This can even be true of humans. A Russian boy named Ivan Mishukov, born in 1998, was raised by dogs for two years and came to believe that he was a dog himself.
