'Sea lice' stinging swimmers off Florida beach

This undated photo provided by Visit South Walton shows Grayton Beach on Florida's Panhandle on the Gulf Coast. Grayton Beach State Park is No. 6 on the list of top beaches for the summer of 2016 as compiled by Stephen Leatherman, also known as Dr. Beach, a professor at Florida International University. (David Bailey Photography/Visit South Walton via AP)

SANTA ROSA BEACH, Fla. – Swimmers at a Florida Panhandle beach are dealing with painful rashes from stinging jellyfish larvae, more commonly known as "sea lice."

The News Herald reports the sea lice are almost invisible to the naked eye, but they leave an unmistakable sting. They've been reported along Walton County's Santa Rosa Beach this week.

Scott Jackson, a sea grant extension agent in nearby Bay County, says some scientists have compared the larvae to specks of pepper. They typically float harmlessly in the water, but sometimes they get trapped inside swimsuits. That's when they sting.

Jackson says they leave behind a rash or bumps on the skin. The rash is often called "ocean itch" and lasts from a couple hours to several days.