Portuguese man-of-wars are as beautiful as they are dangerous. In fact, their beauty is part of their danger. Lots of people—especially kids—just want to run up and touch them when they wash up on the beach. That’s a big mistake.

Here’s the rundown on this incredible life-form, and one very good reason you should definitely stay away if you see one!

First things first: The man-of-war is not a jellyfish.

It looks like a jellyfish. It stings like a jellyfish. But the Portuguese man-of-war is not a jellyfish. Instead, it’s a related order called a siphonophore. Siphonophores must be from outer space because this is how Wikipedia describes them:

“Siphonophores are of special scientific interest because they are composed of medusoid and polypoid zooids that are morphologically and functionally specialized.”

The man-of-war is not even a single animal.

Just to make things weirder, those purple blobs aren’t even discrete organisms. They’re made up of colonies of creatures that work together like the organs in a “normal” animal’s body. Maybe that’s what that “zooid” talk was all about. We don’t know, and there’s no way to find out.

The Portuguese man-of-war will sting you, and you will cry, or worse.

Man-of-war tentacles can dangle below the surface of the ocean for 100 feet (although the average length of the murder-tail is 30 feet.) Tiny barbed needles called nematocysts cover the tentacles.

Those nematocysts are hollow, and the man-of-war can inject potent venom at will, so you won’t want to get close to one of these things.

Portuguese man o' war washed up on beach
Enrique Ortega Miranda on Unsplash

Man-of-war venom can mess you up.

These highly effective hunters just wait around for fish to get tangled up in their tentacles. Then they let loose with a few different kinds of venom.

One element of the poison burns holes in cell membranes. Another dissolves fats and proteins. Again, let us reiterate: You do not want to get stung by a man-of-war.

“If a child gets stung around the neck, it could potentially be a lethal event because so much of the venom can be injected into the bloodstream,” Angel Yanagihara, a professor at the University of Hawaii in Honolulu, told National Geographic.

If you get a sting on thicker skin, your life probably won’t be at risk, but you will be in a world of hurt.

Tentacles retain their power to sting long after the rest of the organism is dead.

Sometimes Portuguese man-of-wars wash up on the beach and drown in the air. That doesn’t mean you’re cleared to reach out and shake hands, though. Tentacles retain their stinging power for weeks.

So take our advice: Don’t touch a Portuguese man-of-war. If you have to touch something, find a sand dollar or something.

If you do get stung by a Portuguese man-of-war, don’t pee on the injury.

Rumor has it that human urine can ease the pain of a man-of-war sting. No, it can’t. That’s an internet rumor, and you should not listen to random voices on the internet (except for this one. Remember when we warned you about not touching Portuguese man-of-wars?)

Instead, apply a cold pack to keep swelling under control. If things get really bad, or you think you might have an allergy, go to the hospital right away.