Table 2.
Ethograms of behaviors scored in the novel cage and the home cage change tests.
| NOVEL CAGE TEST | ||
|---|---|---|
| Functional category | Individual behaviors | Description |
| Proactive coping | Stretched approach | Walking with a flat body posture stretched and close to the floor |
| Stretched attend posture | The rat stretches the neck or front part of the body forwards with four paws on the floor and then returns backwards | |
| Grooming | Scratching, shaking, wiping, or licking body parts (fur, ears, nose, and tail) | |
| Reactive coping | Freezing | Sudden suppression of movements |
| Motionless | Sitting or lying without suppression of movements | |
| Exploratory activity | Free rearing | Standing on hind legs |
| Investigating | Exploring the floor, cage walls, or air through olfactory activity | |
| Locomotor activity | Wall rearing | Standing on hind legs with forepaws leaning against a wall |
| Walking | Locomotor behavior with normal body posture | |
| HOME CAGE CHANGE TEST | ||
| Functional category | Social behaviors | Description |
| Neutral behavior | Head–head | The head of the rat touches the head of the other rat |
| Nose–side | The rat sniffs between the ventral region and the back of the other rat | |
| Nose–nose | The rat sniffs the other rat's nose in an equal sniff | |
| Passing | The rat passes the other rat either in a direct meeting or from behind | |
| Dominant behavior | Head–tail | The head of the rat touches the tail of the other rat |
| Nose–genitals | The nose of the rat touches the genitals of the other rat | |
| Following | The rat follows the other rat for more than two steps | |
| Approaching | The rat is walking or running more than three steps without hesitation with the nose pointed in direction toward the other rat and fulfills the approach with a minimum of 5 cm away from the other rat | |
| Nuzzling | The rat sniffs/bites/grooms the other rat in the area between the tip of the nose and the ventral region | |
| Mount 1 | The rat rears and leans its front legs on the other rat's back from behind | |
| Aggressive behavior | Mount 2 | The rat rears and leans its front legs on the other rat's back from behind and makes copulation movements |
| Chasing | The rat runs after the other rat for more than two steps | |
| Fight | Very rapid rolling, jumping, and biting of both animals while being in close contact | |
| Submissive behavior | Avoiding | The rat moves or faces in a direction away from the other rat when the other rat is approaching |
| Crowing under | The rat is crawling under the other rat | |
| Submissive posture | The rat is lying on its back with the other rat standing and/or leaning over its ventral part | |