The mouse is a nocturnal animal. The nest and the system of burrows and passages which is the animal’s natural habitat, protect wild mice against environmental influences (noise, light, humidity and temperature) as well as against predators. In group housing in a laboratory setting, competition issues can arise and humans can be cast into a predator role.
The laboratory mouse, too, has a need for a “natural environment” with opportunities for burrowing and nesting material (see the movie 1).
bedding material and material that can be used to build nests (such as tissues) are most suitable. When cleaning cages, it is important to transfer a portion of the bedding material to the clean cage to retain scent markings (see the movie 2').