The wolf recently returned to the Netherlands, but in Poland they never vanished. Wolves are social animals that live in packs (family groups). A pack is led by an alpha male and alpha female. Usually these two have the exclusive right to reproduction. The food supply determines the group size. The offspring of the alpha pair usually remain in the pack for about two years and after that often spend another period with their siblings. The wolf has a wide variety of expressing capacities. The well-known howling is primarily intended to communicate over long distances, they can hear each other at distances of 6 to 10 kilometers. Within the pack communication mainly takes place by body language. Submissive wolves e.g. greet others by submission, with averted eyes, tail between the legs, low posture, ears back and a gentle whining. When they are angry or afraid, they usually show this with bare teeth and growling.