Necessary and sufficient conditions for communication of diet preferences by Norway rats

Rats that (1) either ate a small sample of one or two foods (Diet A or Diet B) or interacted with a demonstrator that had eaten either Diet A or Diet B, (2) ate both Diets A and B in succession, and (3) were made ill preferred whichever of the two foods they or their respective demonstrators had eaten. Although eating a food and interacting with a demonstrator that had eaten that food were each sufficient to enhance preference for the food, …