Proceedings of the Vertebrate Pest Conference

We conducted a series of preliminary feeding trials with Norway rats (Rattus norvegicus), roof rats (R. rattus), and Polynesian rats (R. exulans) to examine the effects of carbon disulfide (CS2 on consumption of nontoxic foods. We formulated CS2 at target concentrations of 10 ppm in deionized water, and of 50 ppm to 100,000 ppm in a starch xanthate matrix. However, we did not analyze actual concentrations of CS2 in the test foods or measure its rate of volatilization, and thus cannot verify the levels of CS2 the rats were exposed to CS2 diluted in water and applied directly to food had no apparent effect on consumption by any of the species. Formulations with 50 ppm CS2 in starch xanthate influenced food choice by Norway rats and roof rats in one test, but not in another. Concentrations ≥ 10,000 ppm repelled Norway rats. CS2-starch xanthate had little effect on consumption by Polynesian rats. Further testing is needed to develop effective formulations and delivery methods for utilizing CS2 as a bait additive.