Should we all be worried about the sea fleas that attacked a teenager last weekend?

If you hadn’t already heard, Australian teenager Sam Kanizay had a bad day on Saturday when he decided to take a dip in the waters of Brighton’s Dendy Street Beach. Instead of enjoying a romp in the surf, Kanizay emerged from the water bleeding heavily from his feet and ankles. The culprit? Sea fleas. Now the bigger question—should you be worried?

Kanizay had never heard of the creatures before and wasn’t entirely sure what was happening.

“I walked out of the water, saw what I thought was sand covering my ankles below my calf, shook it off quite violently, and it came off,” he told CNN affiliate Seven Network Australia in an interview.

But what came off wasn’t sand—it was a pack of marauding sea fleas, a type of crustacean. According to a Facebook post by Museums Victoria, the creatures responsible for leaving holes all over Kanizay’s feet and ankles were “lysianassid amphipods, a type of scavenging crustacean,” says Museum Victoria’s marine biologist Dr. Genefor Walker-Smith.

This was only discovered after examining samples of the creatures that Kanizay’s father caught with a pool net and some raw meat. If you’d like to see a truly unsettling video of the sea fleas behaving like vampires, you can watch below.

But the bigger question is this: Should we all avoid the ocean forever? Well, probably not. According to Museums Victoria, “the creatures are naturally occurring scavengers, which commonly bite but do not usually cause these kind of injuries.”

In an interview with the Australian publication The Age, Walker-Smith said there’s probably not much to worry about. You should, however, avoid swimming near dead fish or other animals because the sea fleas will feed on the carcasses.

“I think this is quite a rare thing. I really just think [Sam] was in the wrong place at the wrong time, probably,” she said.

A Victorian Department of Environment, Land, Water and Planning spokesman told BuzzFeed News that sea fleas are a “common and natural part of a healthy marine ecosystem” and they “keep our marine waters clean by consuming dead and dying marine animals.”

So there you have it—no swimming around dead fish and you should be fine.