Abstract
Chipmunks (Tamias striatus), jumping mice (Zapus hudsonius), voles (Microtus pennsylvanicus), deer mice (Peromyscus maniculalus), hamsters (Mesocricetus auratus), house mice (Mus musculus) and gerbils (Meriones unguiculalus) were individually confined in dark cages. A corner of each cage had been marked with dried urine. Animals tended (311 of 461 tests) to urinate in the marked corner. Animals did not usually urinate (except adult gerbils) or defecate (except hamsters) in their nests.
The effect of visual isolation of individual mice was not apparent in organ weights, but did lead to altered behaviour.