This article is from the WSSF 2013 AFRMA Rat & Mouse Tales news-magazine.
Did You Know? Rats will help free a trapped cagemate. In a study done at the University of Chicago, neuroscientists found when they placed two cagemates in a test arena and one was in a restraint, the free one would become agitated. After several sessions, the free rat learned how to open the restrainer door and free its buddy. Once the free rat learned how to open the door, it would take action almost immediately when placed in the test area. The rats were not trained to open the door nor received any reward other than having its cagemate free of the restraint. When a stuffed toy was in the restraint, there was no reaction on the rat to open the door. When the free rat opened the door but it released the trapped rat into another compartment, the free rat still opened the door. When given the choice of freeing the trapped cagemate or opening a container with treats, the free rat was equally likely to free the cagemate before opening the treat container and sharing. Not every rat learned to open the door and females were more likely to be door openers.
To read more and see a video, go to http://news.uchicago.edu/article/2011/12/08/helping-your-fellow-rat-rodents-show-empathy-driven-behavior. Original article in Science magazine.