U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Document Type


Date of this Version



Proc. 24th Vertebr. Pest Conf. (R. M. Timm and K. A. Fagerstone, Eds.) Published at Univ. of Calif., Davis. 2010. Pp. 218-221.


Following the escape of 8 Gambian giant pouched rats (Gambian rats) from an exotic pet breeder in 1999, Gambian rats became an established invasive species that persists in the wild on Grassy Key, Florida. Because of their large body size, the free-ranging Gambian rats pose a serious threat to native species and agricultural crops, especially if they find their way into mainland Florida. Initiated in 2005, the USDA Wildlife Services has been conducting an eradication and detection program in the Florida Keys. Today however, detecting, baiting, trapping, and removing the now sparse population of Gambian rats are proving difficult. Therefore, we conducted a laboratory trial with wild-captured Gambian rats from Grassy Kay to test 15 potential materials that could be used for attracting the remaining free-ranging population. We found that a conspecific scent (i.e., feces and urine) from other Gambian rats was the most attractive, but also peanut butter, anise, ginger, and fatty acid scent seemed to attract Gambian rats. In an additional study, we tested the efficacy of 6 commercially available rodenticide baits (all with different formulations of active ingredients) in multiple-choice food trials. We found that brodifacoum (second-generation anticoagulant) and zinc phosphide (acute rodenticide) formulated baits were highly effective. Using these various attractants and rodenticides could be useful for eliminating the sparse population of invading Gambian rats in the Florida Keys.