Bull snakes, aka gopher snakes, are excellent swimmers ­— a fact that is not exactly welcome news when you’re in the middle of a reservoir in a float tube and one decides to pay a visit. Bull snakes are not venomous and are very common in Southwest Idaho. They’re beneficial for keeping rodent populations under control. But they still freak out a lot of snake haters, and also some pretty snake-tolerant people when they unexpectedly appear. ROGER PHILLIPS — rphillips@idahostatesman.com