灰熊
A United States Geological Survey article, "Bear Spray Safety Program," says that bear spray is effective in fending off aggressive bears while also preventing injury to both the human and the bear. It also states, "No deterrent is 100-percent effective." In "Living with Grizzlies," the U.S. Fish and Wildlife Service states, "The Service supports the pepper spray policy of the Interagency Grizzly bear Committee, which states that bear spray is not a substitute for following proper bear avoidance safety techniques, and that bear spray should be used as a deterrent only in an aggressive or attacking confrontation with a bear."