Many seashore animals bury themselves in the sand, mud or rock. They dig themselves in to try to keep themselves safe from being eaten. Some animals hide in the sand when the tide is out. This stops the animal from drying out in the wind or Sun.
These are lugworm casts on a sandy beach.
Lugworms live in U-shaped burrows on sandy or muddy seashores. They swallow mud and eat any pieces of food they find in it. The sand comes out of the worms’ bottom at the other end of the burrow, and makes a squiggly worm cast on the surface of the mud.
This dog whelk hides in cracks in rocks.
Some shellfish protect themselves by digging into rock or squeezing into gaps between rocks. Dog whelks hide under rocks, crawl into cracks and wedge themselves into crevices on rocky seashores when the tide goes out. When the tide comes back in the dog whelks come out to feed.
Cockles bury themselves in the sand.
Cockles use their muscular foot to bury themselves in the sand. This helps to protect them from being eaten by birds and animals. Cockles and razorshells feed using long siphons that suck water and strain food from it.