The place where rabbits breed is called a warren. Warrens refer to the underground tunnels that some domestic rabbits dig to live in social groups.
The word "warren" can also refer to a disorienting set of city streets or a building that has people packed into it, much like rabbits packed into the burrows. Many wild rabbits create shallow nests to give birth. However, if they are able to do so, many rabbits dig large underground burrows to live in family groups. Rabbits only do so under certain conditions. The area must have enough food to support a large group of rabbits as well as have the right soil.