Native to the United States and Canada, the queen snake, Regina septemvittata, is an aquatic snake that hibernates during the cold winter months. It is a diurnal species, meaning it is most active during the day, when it hunts for food. On average, a queen snake can reach up to 2 feet (60 cm) long. The queen snake has an olive brown upper body, with a creamy yellow underside. This species is not venomous and does not pose any danger to humans.
Preferring rocky-bottomed, moderately shallow, fast-flowing water, the queen snake feeds mostly on crayfish. Shortly after the crayfish has shed its very hard exoskeleton, before the new exoskeleton has had time to harden — so the crayfish is still "soft shelled" — is the point at which a queen snake will eat a crayfish. If crayfish are scarce, the snake will eat frogs, small fish and invertebrates.
The queen snake usually remains close to bodies of water with a ready supply of crayfish. Often found under rocky outcrops or overhangs along the banks of bodies of water that contain a plentiful supply of food, this species can also be spotted basking on top of rocks or amid vegetation along the banks. Sometimes the queen snake can be spotted draped over low-hanging branches above the water, occasionally in large numbers.
The queen snake hibernates from October until April, becoming almost entirely inactive and very lethargic during this time. The snake becomes very vulnerable to predation during this time. The queen snake is at risk from large birds such as herons, as well as mature crayfish. Large crayfish are a particular threat to juvenile snakes, even when the snake is not hibernating. It is relatively common for a juvenile queen snake to be captured by a mature crayfish when hunting.
While still thriving in a few areas, such as Georgia, the queen snake population is declining rapidly in many areas. In areas such as Wisconsin, the queen snake is under state protection but is not yet under federal protection. In Canada this species has extensive protection as a seriously threatened species. In Canada the queen snake is protected under the federal Species at Risk Act, the Canada National Parks Act and the Fish and Wildlife Conservation Act. The main threats to this species are the loss of waterways and the localized decline in crayfish numbers.