Maybe it was the dead fish, or even the horseshoe crab.

And those horseshoe crabs - they look like they're 40 million years old.

The same behavior can be seen in modern horseshoe crabs.

If they are kept moist, the horseshoe crab can live on land for many hours.

I wondered if you could put a price on watching horseshoe crabs with your children.

Perhaps this is why the horseshoe crabs developed the habit.

Once on the beach, the horseshoe crabs don't waste time.

"The horseshoe crab is frightening to a lot of people," he said.

Horseshoe crabs have two large compound eyes on the sides of its head.

The eyes of horseshoe crabs can detect movement but not form images.