Tide pools form when the ocean covers the beach twice a day. Some of the plants and animals that live close to the sea are covered when the tide washes over them. They have to be able to survive in both wet and dry conditions. The tides bring fresh oxygen and food to them. Between tides, some of the smaller pools become too warm and begin to dry up. Many of the animals hide under cool, damp rocks and moist seaweeds so that their bodies do not dry out before the tide comes in again.