Not all snakes are poisonous. In fact, in Michigan there is only one poisonous snake species in all the state- the Eastern Missisauga Rattle Snake, and it is protected. Do not harm snakes, as they are a benefit to the enviornment. With that said, they can carry salmonellosis, or salmonella, and other harmful bacteria that will complicate a wound.
Do not pick up snakes. Even if they are not poisonous, their bit may infect you with bacteria, diseases, or both.