Many animals have not what humans call home, but a territory where they live and where there are often dens or several places to sleep, rarely permanent.

Many animals change their den depending on seasons, such as many rodents that in summer build their nests on trees. When their nests are abandoned, with the arrival of the winter season, often they become homes of other species (such as owls that can stay in the squirrels’ nests).

The nest of the squirrel is a compact ball of twisted twigs, stuffed with shredded bark, moss, grass and leaves. There is no particular entry hole and the edge is elastic enough to allow the passage of the squirrel at any time.

Moles lead an underground existence and then the small earth mounds in a row on the ground follow the route of a deep tunnel, while larger piles can be nests covers.

Marmots live in burrows dug in the ground where they take refuge to escape predators and to escape the summer heat and winter cold. In the marmot’s den there are various structures, only some holes have access to the main dens, other cavities are only temporary shelters or latrines. The main dens are complex structures consisting of one or more access tunnels and more rooms, used for the delivery and rearing of babies. In some cases, the summer and winter lair are separate dens.

Badgers build their burrows, which are considered the most durable, underground and they are sometimes used for centuries being enlarged and cooled over time. A big old hole may extend for more than one hundred meters. Many other animals can find refuge in the badger’s den, such as the fox.

Bears and other animals can also choose as den a cave, if they find it suitable, or they can make a hole at the base of a hollow tree using little material to stuff it.

Caves or other shelters built by man such as tunnels, mines and attics can also accommodate bats, whose presence can be noticed from the excrement and sometimes inedible remains of insects.

The deer do not build proper dens but lies down in sheltered places within the territory where it finds food.

The environment also affects the rest of the wild boar that can just stay in the shelter of a tree or dig a shallow hole with or without leaves inside.

In summer the fox normally rests in the thick grass, but when it is cold it explores any kind of refuge before building its home that often it is simply an enlarged rabbit hole.

Hedgehogs instead build a kind of nest in quiet places such as forests with leaves, straw and well-pressed grass to make its den waterproof.