Rats exhibit supportive behaviour just like us humans. It was discovered that rats are more motivated to participate in grooming with another rat if food was received from it and vice versa. They were found to groom willing food-suppliers more often than those rats that did not share food. As a result, the groomers then received even more food for their efforts. “I help you because you helped me” is the decision rule of direct reciprocity, which was found in those rats that shared food and received grooming as a reward. Reciprocal trading is not limited to large-brained species as shown by bees running their hive or ants in a colony. Until recently, it was thought that the amount of brain power required to do this kind of interaction was over taxing their abilities and unlikely to happen.
gogreenpestcontrol.ca Ladner Tsawwassen Delta B.C. Randy Bilesky
https://www.linkedin.com/pulse/rats-i-help-you-because-helped-me-randy-bilesky/?published=t
http://www.delta-optimist.com/opinion/blogs/blog-rats-i-help-you-because-you-helped-me-1.23164744