Table 5.

Definitions of specific physical interactions.

Behaviour	Definition	Type
Anogenital sniffing	The rodent sniffing the anogenital areas of the conspecific	Social investigative (neither friendly nor hostile)
Crawling/mounting	The rodent crawling over the conspecific	Prosocial
Digging	The rodent digging a hole into the bedding of the apparatus	Compulsive/repetitive/anxious
Fighting	Fighting in adults (approximately PD 90-120)	Hostile
Non-anogenital sniffing	The rodent sniffing the non-anogenital areas of the conspecific	Prosocial investigative (friendly)
Pinning	The rodent standing over the conspecific which lies flat on its back	Prosocial
Play fighting	Fighting in juveniles (approximately PD 30-50)	Prosocial
Play responsiveness	The probability of being pinned in response to being pounced on	Prosocial
Rearing	The rodent standing up on its hind legs	Environmentally investigative