Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment

For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare, such as ‘establishment’: a hypothetical process whereby repetition increases behaviour’s predictability and resistance to change. If such hypotheses are correct, […]

The motivation of group-housed laboratory mice to leave an enriched laboratory cage

Animals used in research are often housed in small, barren cages. Providing environmental enrichment should improve their welfare, and a consequence of this might be a reduction in the animal’s motivation to leave an enriched cage. I examined this possibility by housing laboratory mice, Mus musculus, in a cage that provided cagemates, food, water, large […]

From house mouse to mouse house: the behavioural biology of free-living Mus musculus and its implications in the laboratory

Understanding a species’ behaviour in natural conditions can give insights into its development, responses and welfare in captivity. Here, we review research and pest control literatures on the free-living house mouse (Mus musculus), analysing its sensory world, developmental processes and behaviour to suggest how laboratory environments might affect mouse welfare, normalcy, test design, and behaviour. […]

Environmental enrichment, immunocompetence, and resistance to Babesia microti in male mice

Groups of male CFLP mice housed in cages furnished with shelves and nestboxes showed increased aggression and reduced resistance to an experimental infection of Babesia microti when compared with groups in unfurnished cages. Both a bystander measure of immunocompetence (serum total IgG concentration) and resistance to B. microti decreased as the number of attacks received […]

Hormonal stress response of laboratory mice to conventional and minimally invasive bleeding techniques

Conventional bleeding of small laboratory animals is often associated with stress and injuries that can cause haematomas, inflammation and ultimately the death of animals under investigation. Here, we used faecal glucocorticoid metabolites as an indicator of stress imposed on laboratory mice (Mus musculus domesticus) when bled in three different ways: puncture of the tail vein […]