Rats move nesting materials to create different functional areas: short report

Here we documented how rats separate their living space into different functional regions. Five groups of female Sprague Dawley rats were housed in two-caging systems that consisted of two standard cages connected by a tube. Both cages were provided with the same amount of bedding and nesting materials, but only one contained food and water. Nesting cover and weight of each cage were measured once a week for five weeks during cage cleaning. We found that the cages with food and water had 9% less coverage but had gained 90% more weight when compared to cages where food and water were absent. These results indicate that, when provided with separate spaces, rats move nesting materials away from the cage containing food and water sources, but preferentially excrete in cages with water and food.