PREFERENCES FOR NESTING MATERIAL AS ENVIRONMENTAL ENRICHMENT FOR LABORATORY MICE

Behavioural and psychological needs of laboratory animals generally ca nnot adequately be met in standard laboratory cages. Environmental enr ichment, which provides a more structured environment can enhance the well-being of laboratory animals. They may perform more of their speci es-specific behaviour and may control their environment in a better wa y. An easily applicable form of enrichment for laboratory mice is nest ing material. Six different types of nesting materials were evaluated in a preference test with male and female animals of two strains (C57B L/6J or BALB/c, n=48). No significant differences in preference were f ound between the strains or between the sexes. All mice showed a clear preference for cages with tissues or towels as compared to paper stri ps or no nesting material, and for cages with cotton string or wood-wo ol as compared to wood shavings or no nesting material. Paper-derived materials were preferred over wood-derived materials, although the res ults also suggest that the nature (paper or wood) of the nesting mater ial is less important than its structure, which determines the nestabi lity of the material. Nesting material may be a relatively simple meth od to contribute to the well-being of laboratory mice.