Heath, M. 1999. Preliminary behaviour data for single and pair housed rats. Animal Technology 50, 47-48.

Singly housed rats spent most of the time in the back of the cage, while pairs spent most time by the food hoppers. This may have been exacerbated by the presence of humans, as pair housed rats were more confident overall. Activity patterns were very different between singly and pair housed rats, in term of both the total time spent doing different things and the time when specific activities occurred. In particular, single rats spent far less time playing than pair housed rats.