Laboratory mouse aggression study

The NC3Rs is leading a data crowdsourcing project for animal technicians to collect data on the prevalence and potential triggers of cage aggression in group-housed male mice. 

Mice are used extensively for the purposes of scientific research, with over 2.8 million mice being used in the UK in 20161 alone. Increasing understanding of the potential triggers of mouse aggression could have a big welfare impact on a significant number of laboratory animals.  

The data collection phase of the study is now closed. Thanks to all of the technicans who participated. We are currently analysing the data and hope to make the results available in Autumn 2018. 

If you have any queries about the study, please contact

Background reading

There are many publications on the subject of mouse aggression in the literature. A few notable papers are given below:


  1. Bussell J, Wells SE (2015). Talking welfare: the importance of a common language. Mamm Genome 26: 482-485. DOI: 10.1007/s00335-015-9591-x
  2. Charles River (2012). Reducing aggression in mice. Technical Sheet. (accessed 29 August 2017).
  3. Gaskill BN (2014). Aggression in laboratory mice: potential influences and how to manage it. The Enrichment Record Winter 2014: 22-25. (accessed 29 August 2017).
  4. Hurst JL (2005). Making sense of scents: reducing aggression and uncontrolled variation in laboratory mice. (accessed 29 August 2017).
  5. Kappel S et al. (2017). To group or not to group? Good practice for housing male laboratory mice. Animals 7(12):88. DOI: 10.3390/ani7120088
  6. Weber EM et al. (2017). Aggression in group-housed laboratory mice: why can't we solve the problem? Lab Animal 46: 157-161. DOI: 10.1038/laban.1219
  7. Van Loo PLP et al. (2003). Male management: coping with aggression problems in male mice. Lab Animal 37: 300-313. DOI: 10.1258/002367703322389870

Research papers

  1. Annas A et al. (2013). Group housing of male CD1 mice: reflections from toxicity studies. Lab Animals 47: 127-129. DOI: 10.1177/0023677213476278
  2. Gaskill BN, Prichett-Corning KR (2015). The effect of cage space on behaviour and reproduction in Crl:CD1(Icr) and C57BL/6NCrl laboratory mice. PLoS One 10: e0127875. DOI: 10.1371/journal.pone.0127875
  3. Gaskill BN et al. (2017). The effect of early life experience, environment, and genetic factors on spontaneous home-cage aggression-related wounding in male C57BL/6 mice. Lab Animal 46: 176-184. DOI: 10.1038/laban.1225
  4. Lockworth CR et al. (2015). Effect of enrichment devices on aggression in manipulated nude mice. J Am Assoc Lab Anim Sci 54: 731-736. PMCID: PMC4671788


The NC3Rs is grateful to the Mary Lyon Centre, Harwell Institute, the Laboratory Animal Science Unit, AstraZeneca, Alderley Park and the Sanger Institute for their contributions to the pilot phase of the study.


1Home Office report - Annual Statistics of Scientific Procedures on Living Animals Great Britain 2016 (accessed 29 August 2017).