Bull Snakes are NON-VENOMOUS, which means NO, they are not harmful to humans. On the contrary, they are very, very useful animals to have around, since they eat rodents like rats, mice and gophers, which CAN be very harmful to us by spreading diseases and eating our crops and food. Snakes are the most effective controls of these fast-breeding rodents; without snakes we humans probably would have died out long ago, from deadly rodent-bourne diseases like Bubonic Plague, Leptospirosis, Hantavirus and Typhus, and from starvation. The risk of even venomous snake bite death, especially in the United States, is very low compared to that of contracting a deadly disease from rodents. Rats, mice and squirrels chewing on electrical wiring is also a major cause of house and structure fires in many areas, another reason to be grateful for snakes!