The castor is herbivore .He eats leaves, crust from trees and fresh wood. His tail hasn´t got any bristle.He uses it as helm. When a custor feel danger,he splashes with his tail on water-he warns remaing custors. The custors has got big sharp teeth and with his teeth gnaw trunks trees. When there is a lot of water in the river,the custor makes dam.He controls the water state with it.Some dams are long 120 metres and they are sometimes 3 metres tall. They have got a number of entries and all entries are under the water. The water is frozen in winter. The custor can´t go out,there is an air shaft from limbs.

Reproduction:
On springtime female produce 2-5 cubs.The cubs can see at first day. The custor is nice and useful animal,but in the past he was almost perish in Europe.