Surely many people think that dogs cannot have any secrets: we are used to living side by side with these animals.
In ancient times, it was dogs that helped humans develop animal husbandry, as they participated in guarding livestock and acted as shepherds.
However, dogs are not as simple as they seem.
You've probably heard that before starting a family, many people are advised to try looking after a dog first. This is really good advice.
Experts note that the dog is at the developmental level of a small child.
Few people know that such strange collars were invented for a practical purpose. It was believed that the accessory would help protect the dog's life when meeting a wild animal.
The device was invented by the ancient Greeks.
A human, for example, has a set of nine thousand receptors that are responsible for determining taste. But dogs have almost twice as many.