Table 1.
Description of social and non-social mouse behaviors.
| Domain | Behavior | Description of the behavior of the focal mouse |
|---|---|---|
| Social behaviors (involves at least two individuals) | ||
| Affiliative | Allogrooming | The mouse is licking or grooming another mouse |
| Huddle | The mouse is lying and/or sleeping in contact with another mouse (only scored in chambers) | |
| Defensive | Flight | The mouse moves rapidly away from an approaching animal |
| Offensive aggression | Chasing | The mouse moves rapidly toward a fleeing animal (faster than following) |
| Contact | The mouse moves toward another animal from a distance. The movement ends with physical contact with the target animal (not counted in chambers). | |
| Struggle | The mouse moves toward another animal and rolling-and-biting follows. | |
| Struggle at feeder | At feeder only. The mouse pushes another mouse without boxing or biting (otherwise counted as “struggling” or “biting”). Two separate “struggling at feeder” are counted when there is an in-between pause of >1 s. If the pause is < 1 s, only 1 “struggling at feeder” is counted. | |
| Mounting | The mouse mounts on the back of another mouse and shakes its hip quickly (similar to sexual behavior). | |
| Biting | The mouse is clearly biting another animal. | |
| Social approach/communication | Approach to front | The mouse moves toward the front of another animal from a distance. |
| Approach to back | The mouse moves toward the back of another animal from a distance. | |
| Following | The mouse follows, at walking speed, the trajectory of another animal (slower than chasing). | |
| Sniffing | The mouse is sniffing another animal. Sniffing is not counted in the chamber and when it is done during the general exploration of the environment. | |
| Other behaviors (alone or in the proximity of others) | ||
| Maintenance | Drinking | At the water spout, the mouse is drinking (repetitive head and tongue movements directed toward the spout) |
| Eating | At the feeder, the mouse is eating (repetitive pulls with the head from the magazine or paws) | |
| Grooming | The mouse is licking its own fur/paws/tail (repetitive head bobs) | |
| Activity | Moving | The animal moves from one location to another and this is not a movement of another behavioral domain |
| Immobile | The animal shows minimal amplitude of movement to no movement | |
Behaviors are grouped by domains (Lewejohann et al., 2010). In bold are behaviors classically scored in VBS studies in mice (Arakawa et al., 2007), and in regular font are other behaviors often scored in studies of social behavior. Mounting in same sex males is listed as offensive aggression following the work of Karigo et al. (2020). The following behaviors: “being bitten”, “being sniffed”, “being mounted”, “being groomed” were scored but not analyzed to avoid redundancy with “sniffing” and “allogrooming”.