“It's usual to see, after they've eaten, them stretching out and realigning their jaw. They do this whenever they need to and it's certainly not because they're tired.” While it's a myth is that snakes unhinge their jaws, the upper and lower jaws are made up of two parts that move independently of each other.

Most snakes cannot take bites and must engulf prey whole. To do so, a typical snake opens its mouth at the joint in the middle of its jaw, and the two halves of the lower jaw flare out to the sides; the skin and tissue in between stretch to accommodate the food.