Aggression and fighting
- Males may be combined at weaning age (3-4 weeks), but should not be combined at older ages. They may fight, cause wounds and/or death of male cage mates.
- Males shipped in separate compartments of the same shipping box or in individual boxes should not be combined upon entry into your facility as they may fight. Wounded mice may not be useable for your research.
- Separate group-housed males which are fighting; at the very least remove the dominant male (the mouse lacking wounds).
- Males from some strains (e.g. SJL/J) are naturally aggressive toward their female mates and offspring and may need to be removed until pups are weaned.
- Housing density of mice can affect aggressive tendencies. Consult your institutional ACUC for housing density guidelines.
- Change gloves frequently and use forceps disinfected between cages to reduce scent transfer that can lead to increased aggression.
- Providing environmental enrichment such as nesting materials, Nestlets (Animal Specialties and Provisions, LLC), NestPaks (WF Fisher and Son), and Shepherd Shacks (Shepherd Specialty Papers) can help alleviate stress and aggression.
