Clean Living is a Luxury Wild Mice Cannot Afford

New research suggests that domesticated mice have a preference for clean eating and sleeping environments that their wild counterparts cannot afford, a find that may lead to a better understanding of how disease spreads among animals.

Researchers from the University of California, Santa Cruz and University of Edinburgh found that wild mice prefer to eat and sleep near used nesting material and droppings left by other mice.

Domestically reared mice are more picky, tending to develop an aversion to dirt. The researchers suggest that regular and reliable access to food and a lack of predators leads pets and domestic animals to be more choosy about where to eat and sleep.

For the study, the researchers used two types of wild mouse found in Virginia. The mice were collected from the woodland and placed in a container for several hours. One end of the container was covered in mouse droppings; the other was not. The mice were free to choose which side of the container to go to. A similar experiment was later carried out using fresh and soiled nesting material.

The wild mice gathered closer to the feces and used nesting material, despite there being cleaner options in either case.

The researchers note that the mice do this regardless of an increased risk of contracting parasites.

"Domesticated animals generally avoid feces to reduce the chance of parasitic infection, but this study shows that wild animals are more concerned with the risk of starvation than with table manners, taking any opportunity to feed. They may even associate feces with safety -- a spot where a mouse has lived long enough to nest and poo is probably pretty safe -- and that is worth the risk of disease," said University of Edinburgh's Patrick Walsh, who took part in the study.

"This helps us learn more about how diseases spread in the natural world."

Walsh and his colleagues' research is published in the journal Animal Behavior.