This rattlesnake is a type of venomous Pit viper, and one bite of it can harm a human. The poison of the Querètaro Dusky Rattlesnake is hemotoxic, meaning the poison effects the blood of a humans body. However the Querètaro Dusky Rattlesnake does not bite many people because it likes to be left alone; it will only bite a person if the person attacks it or annoys it.