1. What Happens When a Jellyfish Stings?

A jellyfish sting is a defensive reaction that occurs when you make contact with a jellyfish’s tentacles. These tentacles are covered in thousands of microscopic, venom-injecting cells called nematocysts. When touched, these tiny stingers fire like miniature harpoons, injecting venom into the skin, which causes the pain and irritation you feel. It’s a natural defense mechanism for the jellyfish. A critical safety fact to remember is that even jellyfish washed up on the beach can still sting, as their stinging cells can remain active long after the animal is dead.

Now that you know what a sting is, here’s how to recognize one immediately.