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NC3Rs: National Centre for the Replacement Refinement & Reduction of Animals in Research
CRACK IT Solution

Rodent Big Brother

The Home Cage Analysis system

At a glance

Award date
June 2015
Contract amount


  • Refinement


Rodent behaviour analysis plays a vital role in drug discovery, from the development of disease models through to safety pharmacology. In research laboratories, rodents live in small social groups in highly optimised plastic home cages where they eat, drink, sleep, interact and behave, yet these data are not captured due to technical challenges. Instead, this home cage behaviour data is either ignored, or single animals are removed from the home cage to be monitored on their own. This is sub-optimal from an animal welfare perspective as single housing is stressful and may induce artefacts.

Through the CRACK IT Challenge, Rodent Big Brother, the team at Actual Analytics Ltd led by Professor Douglas Armstrong has developed an innovative home cage analysis system that provides 24/7 monitoring of rodent behaviours in a group-housed environment that is beneficial from both the quantity and quality of data generated and animal welfare perspectives. Initial studies focussed on rats in safety pharmacology where warnings of adverse side-effects are more likely to be caught during 24/7 analysis. The system they have developed uniquely tags each individual animal so they know their identity within the group and add onto this video analytics to record and analyse behaviours including activity/immobility, rearing and climbing, circadian rhythms and social grouping.

Funded through CRACK IT Solutions, Actual Analytics is now working with researchers from Queen Mary, University of London to expand the scope of the system and validate it against applications outside of drug development where animal welfare is a pressing concern. Here they propose to validate longitudinal monitoring of home-cage behaviours in animals that have undergone spinal cord injury procedures. In particular they want to assess relevant indicators for animal welfare and functional recovery. Furthermore, it would hopefully provide more insightful understanding of the applicability of this approach for chronic pain assessment that could be translated to other interventional long term models.

Full details about this CRACK IT Solution and the outputs of the funded project can be found on the CRACK IT website.


  1. Yip PK, Chapman GE, Sillito RR, et al. (2019). Studies on long term behavioural changes in group-housed rat models of brain and spinal cord injury using an automated home cage recording system. Journal of Neuroscience Methods. 321: 49-63. doi: 10.1016/j.jneumeth.2019.04.005