The bathing suit areas of Florida swimmers are under attack by an invisible enemy: sea lice. ABC News reports experts expect to see widespread outbreaks of sea lice this summer, especially in the Gulf of Mexico. Sea lice are incredibly tiny jellyfish larvae that are invisible in the water. They get stuck between swimmers' skin and bathing suits or hair and start stinging. That leads to seabather's eruption—aka pika-pika or ocean itch, according to CNN. The itchy rash can last for two weeks. KTRK reports it can also cause chills, nausea, and fever.
Authorities say the best way to avoid the rash is to wear as little clothing as possible while swimming. If you do get stung—you likely won't notice until a few hours later when the itching starts—rub the area with sand or a credit card's edge, then rinse with hot water. Swimmers in areas where sea lice are present should take off their swimsuits before showering and rinse them with vinegar or rubbing alcohol. Outbreaks of sea lice have already been confirmed in Florida, and the tiny creatures are possibly heading toward Alabama, WKRG reports. (More ocean stories.)