Dahlborn, K., van Gils, B. A. A., van de Weerd, H. A. et al. 1996. Evaluation of long-term environmental enrichment in the mouse. Scandinavian Journal of Laboratory Animal Science 23(Supplement 1), 97-106. (Conference Paper)
It appears that mice who were enriched with both objects [nest box and plastic tube] and nesting material were more active, and spent less time on feeding and drinking, and they weight less compared to...