How Elephants Avoid Sinking in Mud

People have long marveled that an elephant, so massive and heavy, can walk calmly through swamps where other animals would struggle.

It comes down to the unique structure of its legs. An elephant’s foot is essentially encased in a leathery pouch. The bottom of this pouch is firmly attached to the foot bones, while the walls of the pouch rest freely on the surrounding muscles. When an elephant steps down, it puts its full weight on the leg, causing the leg and foot to swell and expand. Then, as it lifts its foot to take a step, the leg compresses.

That swelling prevents the foot from sinking into the mud. As soon as the elephant lifts its foot, the foot becomes slimmer and easily pulls free from the mud.