If you are stung by a horseshoe crab's sting, it may cause a puncture and pain, but it is generally not poisonous. The horseshoe crab is a marine creature whose spines are a protective device used to ward off predators or capture prey.

It is this ancient creature that has a type of hemagglutinin in its blood that can be used in modern medicine. of various pharmaceutical reagents, such as insulin and COVID-19 vaccines. In recent years, due to excessive human exploitation, the horseshoe crab population has declined sharply and is even on the verge of extinction.