Evaluation Of Snap-Traps As A Non-Chemical Control For A Brown Rat Infestation

A field trial on a typical market-leading rat snap trap for the control of a Brown rat, Rattus norvegicus, infestation was undertaken. The purpose of the trial was to assess the efficacy of the trap in a rural rat infestation and record observations regarding humaneness. The initial infestation was estimated at approximately 778 rats. During the 21 days of trapping, a total of 105 rats were caught, that is less than 14 % of the initial infestation. Post-21 days trapping, the size of the infestation had increased by 18.5 % to approximately 930 rats. Adult rats avoided the traps to a greater extent than juvenile rats, 79 % of the rats
caught were juveniles and their capture had no effect on the fecundity of the infestation. In total, 37 % of rats caught were caught by a body part that would have likely resulted in a painful, distressing and inhumane death. Three rats were caught but still alive when the traps were checked and not would have not experienced a quick and humane death had they not been humanely culled. Four non-target Wood mice (Apodemus sylvaticus) were found dead in the traps. Therefore, the snap traps were highly ineffective, and extremely time consuming, in controlling the significant Brown rat infestation and from the body position of the snap trap strike, concerns over their humaneness for both target and non-target animals are also raised.