I've worked there. Even a simple bite that does not kill you can give you an infection that will last the rest of your life. As stated above the expression "trash mouth" applies. Sometimes when they catch a large animal they bite it and back of and wait for it to die from the toxins in their mouth. One of the rangers said it can take from a few hours to a day or more, and they just wait, so they don't get hurt. They can then eat the animal when it is weak and can not fight back.