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 predatorsPredator Living at the expense of other animals by killing them. A predator is an animal that feeds itself by killing and eating other animals.. 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 materialBedding material The material (also called “substrate”) used to cover the floor of a cage. This material needs to be absorbent, non-toxic, non-dusting and comfortable to the animals. to the clean cage to retain scent markings (see the movie 2′).