NATURAL FOOD AVERSION IN NORWAY RATS

During a single 1-hr feeding test, adult male Norway rats were offered intact carcasses of adult male rodents, sacrificed by CO2 asphyxiation. In Exp I, 79 Ss fed more readily on conspecifics dead 24-220 hrs than on conspecifics dead 10 min or 6 hrs. In Exp II, 22 Ss fed readily on roof rats (Rattus rattus) whether they had been dead 10 min or 24 hrs. In Exp III, 15 Ss rendered anosmic by zinc sulfate treatment fed more readily on conspecifics dead for 10 min than did 17 controls. In Exp IV, 34 Ss consumed more flesh from house mice coated with roof rat urine than from mice coated with Norway rat urine. It is concluded that Norway rats exhibit a natural aversion to feed on the intact carcasses of freshly sacrificed adult conspecifics in the sense that they are more likely to feed on other species of rodent. The aversion diminishes with the dissipation of the chemoreceptive cue(s) identifying the carcass as a conspecific. (64 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.