To enrich or not to enrich: providing shelter does not complicate handling of laboratory mice.

Environmental enrichment (EE) is used in laboratory animal housing to provide stimuli exceeding those of barren cages and is intended to improve the welfare of captive animals. It is argued that when laboratory mice can routinely retreat in sheltering objects when humans are present, they do not habituate to humans and continue to shy away, thereby increasing the time needed for husbandry and testing procedures. To this date very limited research has been carried out to determine whether providing EE in the form of shelter interferes with the habituation of mice to humans and thus complicates catching and handling them.