How can a bigger tube fit inside a smaller tube?
This might sound like a riddle, but it's a practical dilemma in our snake-eat-snake world.
This eastern king snake, for example, has a mouthful of a Texas rat snake, but the rat snake's longer than it is.
So how can the king snake possibly swallow it whole?
This is just one of countless predatory dilemmas snakes have solved.
Since slithering onto the scene some 150 million years ago, evolving length and limblessness out of their ancestral lizard forms, snakes have diversified rapidly.
Their noodly bodies and flexible heads granted them access to novel places and prey.
And today, there are nearly 4,000 snake species spanning habitats high and low, wet and dry.
All are carnivorous, but their diets range from fish eggs to alligators.
Jaw-dropping anatomy allows most snakes to swallow their meals whole.
