CAT ALERT: INNATE AVERSION TO CAT ODOURS

This section is 1 min long, with soundtrack

Chapter size: 9.1 MB (.mpg) or 1.7 MB (.mov).

Topic and Behaviours covered: innate avoidance of predator odours (see commentary below)

Chapter commentary:
Eating is not the only problem. Avoiding being eaten is another danger that small creatures face. The visit of an unwelcome guest sends the colony bolting into their burrows.

But rats do not need to see a cat to appreciate the danger. They have evolved an innate aversion to cat odours. It makes good sense to stay away from areas visited by such formidable predators, and despite generations that have never encountered a cat, these rats still show this innate aversion. Not all the rats witnessed this cat's visit, yet our whole colony stopped venturing out to take food for the rest of the day, preferring to rely on stored foods until they judged the danger had passed.

One way that mammals avoid predation is to come out at night. Rats are naturally nocturnal, and as the weeks progress, the colony is becoming increasingly active after sunset (see next section).

The inside story. A note from the authors:
The story behind this clip is that, unexpectedly perhaps, it was the cat that seemed the most traumatised by the experience! He was a pet that we introduced in the colony for a couple of hours. After an initially enthusiastic exploration (during which the rats went into hiding), the cat decided to poke its head in the entrance of a burrow and was promptly rewarded with a nip on the nose by an outraged resident. Our fearsome predator spent the rest of time looking rather embarrassed and sheepish, and happy to go home. Apologies, cat lovers.