Odberg, F. O. 1987. The influence of cage size and environmental enrichment on the development of stereotypies in bank voles. Behavioural Processes 14, 155-173.

Bank voles were bred and lived in 4 different environments: small barren cages (SB), small enriched cages (SR), big barren cages (BB) and big enriched ones (BR). Ten different behaviours were recorded at the age of 30, 45, 60, 61, 75 and 90 days. Between day 60 and 61, within each experimental environment, the group of voles performing stereotypies (ST) and the group of those which did not (NST) were each split in two, one part being transferred to a new environment, the other remaining in the same as control. For each of the 10 behaviours, differences between the 4 environments and therein differences between the ST and the NST animals and between the age groups were analysed with a split-plot ANOVA.