In Florida, this is the time of year when everyone flocks to the beaches for some fun in the sun. Kids build sand castles; grown-ups work on their summer tans; and everyone leaves happy, relaxed, and tired. This year, though, more than 800 people found their beach experience less than relaxing. That’s how many were stung by a species of jellyfish known as the mauve stinger.

Like many sea creatures, jellyfish migrate. Periodically, the ocean winds push them to the beaches where they get washed ashore. Atlantic coast beach-goers are used to seeing Portuguese Man ‘O Wars and cannonball jellyfish wash up on the beaches. This year is one of those times, but the species was entirely different.

For the most part, jellyfish stings are pretty harmless, like a bee sting or an ant bite. The often produce some burning and itching and sometimes a rash. Unless a person is actually allergic, the side effects are more bothersome than dangerous. Lifeguards have a solution on hand to neutralize the stings. According to Eisen Wicher of Brevard County Ocean Rescue, only 2 people were taken to the hospital for respiratory problems after being stung.

Thousands of people stayed away from the waters at the beaches in Florida. Many of them left altogether, heading for pools or other places where there are no jellyfish.