Penguins use their feet and tail to help them swim. They can swim up to 15 miles per hour. Swimming that fast helps them get away from predators that might eat them. Penguins spend a lot of their time swimming. Penguins are slow on land because they waddle their feet instead of walking. They sway their body from side to side while they waddle their feet. Sometimes, they also slide down hills on their belly which is much faster than waddling. Sliding helps them get to places faster.