Schroen, A., Dunbar, M., Hughes, L. J. 2014. Useful rodent enrichment: Party in a bag. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 575-576. (Abstract #P102).

Based on standard practice, all laboratory animals should be given enrichment for physical and mental wellbeing. However, depending on the type of enrichment, it can become costly or impede with accurate health observations. We assessed different types of enrichment to determine if we could identify one that would be the least labor intensive and preferred by our mice. We compared singly housed male and female mice under 3 enriched conditions, a cotton bag stuffed with paper strips, a circular disk of bound paper strips, and our standard facility enrichment (a toilet paper roll, paper strips, and a cotton fiber square). Two cages, containing either a single male or single female mouse (weanling aged) were setup for each type of enrichment, and observed for a 3-wk period. A score chart was developed and photographs were analyzed to determine the use of the enrichment and nest quality by each mouse. The enrichment was replaced weekly. The males were indiscriminate towards the type of enrichment and had better quality nests earlier on than the females. By the second week all mice of both sexes formed nests with the standard enrichment and the cotton bag enrichment. The female mice in the same time period separated the circular disk enrichment, however did not create a nest with it. In summary, the least labor intensive and most preferred enrichment amongst our mice would be the cotton bag stuffed with paper strips. Not only can it be used as enrichment for mice but it allows for easy health observations by animal care staff. It can also serve as a visual indicator of mouse health status by latency to build and the quality of their nest.