Humans catch hundreds of thousands of horseshoe crabs every year for their blood

During the warmer months,especially at night during the full moon, horseshoe crabs emerge from the sea to spawn. Waiting for

them are teams of lab workers who capture the horseshoe crabs by the hundreds of thousands, take them to labs, harvest their

cerulean blood, then return them to the sea.Oddly enough, we capture horseshoe crabs on the beach because that's the only

place we know we can find them.