Hohlbaum, K. et al. Sci. Rep. 10, 11165 (2020)
Single housing is a common approach to prevent aggression in male laboratory mice, but social isolation can have negative welfare implications. Separated pair housing (in which a cage divider separates the cage into two compartments, allowing sensory contact while preventing fighting) is an alternative but the long-term effects of this strategy are not known.
A team led by Kristina Ullmann from Charité, Berlin compared the well-being of adult male C57BL/6JRj mice after eight weeks in different housing systems (single-, pair-, or grouped-housed). Their results did not reveal clear long-term beneficial effects of separated pair housing compared to the other housing conditions, but transfer from single to pair housing at week 8 for a few weeks slightly improved the well-being of the mice.