"Bison Enjoying A Dust Bath, Yellowstone National Park, Wyoming" by Catherine Sherman A bison bull wallows along the Yellowstone River in the Hayden Valley of Yellowstone National Park, Wyoming. According to the National Park Service: "For bison, wallowing is when they roll on the dry ground in a "dust bath." A common explanation for the wallowing behavior relates to relieving skin irritations, whether that is from shedding a winter coat or seeking relief from biting insects. Bison will lie down and roll repeatedly onto their sides to stop insects from biting them. Rolling on the ground also creates a layer of dirt on the body that forms a defensive barrier from ticks and lice. Wallowing is also sometimes seen as a social behavior associated with play, group cohesion, and male-male conflict. During mating season, or rut, sexually mature males will urinate in the wallow before rolling on the ground to advertise their physical condition to other males. Who knew the simple act of rolling in the dirt had so many purposes for bison? Wallowing behaviors change depending on the season, time of day, and temperature. If you have a dog, have you ever noticed how they prefer to sleep on the cool hardwood floors instead of the carpet during the summer? This is because carpets act like an insulated blanket, making your dog hotter. Therefore, they try to find the coldest places in your house, often the hardwood floor. Bison exhibit a similar behavior during summer months, because they will lie in the dirt to cool off since soil temperatures are cooler than the grass. They have little hair on their stomachs, so the soil helps cool them down during the summer months."