People have always been interested in animal communication and scientists have done a lot of research this subject. Most animals communicate by smell. Dogs are famous for this. When a dog walks outside, it learns about other dogs by (smell) things. Dogs (help) the police since a long time ago. Everyone has heard birds singing. Research has shown that many other animals use sounds (communicate). Frogs and insects communicate with sounds. Usually the "men" make sounds to invite the " (woman)". Whales and elephants use sounds to communicate. These sounds can travel very far through water or the ground. However, it is (possible) for humans to hear some of the sounds. They are too low or too high for us. Animals have always used body language to communicate as well. a dog puts its tail under its body, it is scared. When a dog wags its tail and (open) its mouth, it is happy.
