Besides using traps, another method to rid your boat of rodents which works is to use the Raid bug bombs which smoke. They work by placing the smoke unit into a tiny bit of water in the bottom of the supplied plastic cup. Place several in a forty-foot boat, and I can pretty much guarantee you the rodents will evacuate and the bugs will die. No rodent carcasses to deal with. Rich Gano Calypso (GB42 Hull # 295) Panama City area, FL