Horseshoe Crabs

Horseshoe crabs are very old animals that have lived on Earth for a long time. Their round, hard shells look like the shape of a horseshoe. They are not really crabs at all. They are more closely related to spiders and scorpions.

Living Fossils

Horseshoe crabs have been around for about 450 million years. That means they lived before the dinosaurs. They have barely changed in all that time. Scientists call them living fossils because of this. Their bodies are built for life on the ocean floor.

How They Live

Horseshoe crabs walk along sandy and muddy sea bottoms looking for food. They eat worms, clams, and other small creatures. Every spring, thousands of them crawl onto beaches to lay eggs. The females dig holes in the sand and cover the eggs up. Shorebirds love to eat the eggs.

Fun Facts

• Horseshoe crabs have blue blood because of the copper in it.
• They have 10 eyes all over their bodies.
• Their blood is used by doctors to test medicines and keep people safe.

Did You Know?

A horseshoe crab can flip itself back over using its long tail if it gets stuck on its back.