The COST Action GroupHouseNet aims to facilitate the prevention of damaging behaviourin group-housed pigs and laying hens. One area of focus is on how genetic and genomictools can be used to breed for animals that are less likely to develop damaging behaviour.The behaviours we are focusing on are feather pecking in laying hens and tail biting in pigs.Both species are kept in groups, and identifying actual performers of this behaviour (peckersand biters), and tracking them at the individual level remains challenging, but is essential forbreeding programs. It is possible to use traditional behavioural observation, but this is timeconsumingand costly. Sensor technology is a rapidly developing field and may offer solutionsfor phenotyping animals at the individual level. We propose that sensor technology combinedwith genomic methods may be useful in solving the problems of damaging behaviour in grouphousedpigs and laying hens. When evaluating the sensor technologies used until now, forlaying hens RFID and accelerometer-based approaches seem most promising. In pigs, computervision is already used to record technical performance, and there seems to be potential forexpanding this approach to the recording of damaging behaviour. If sensor signatures andgenomic fingerprints of individual animals can be combined, this would significantly improveour possibilities to reduce damaging behaviour through genetic selection.