Den

The den is the player's home/house.

Expanding
To expand your den, you need to tap or click on where you want to dig, assign a wolf, fox, bear, wild cat, or dragon to do it, and they'll walk over and start digging.

Note: You will have to use meat when you assign an animal to dig.

Types of Dens
There is only 1 types of den so far in the game. It is unknown if there will be another one or more added in a future update.