The entire length of the beach is covered in black shells of cerith snails in St. Petersburg, Florida
A bizarre video shows millions of snails taking over a popular beach in St. Petersburg Florida.

The entire length of the beach is covered in what looks like black rocks, but are in fact cerith snails.

The filmer wrote online: 'I grew up in Florida and have spent most of my life on the water. I have never seen or heard of this happening before.'

The video only shows about one-quarter of the total invasion of snails.

Cerith snails don't often come onto land. They are usually found on sandy bottoms, flat reefs, or coral rock in warm and temperate areas.

The snails were found south of the parking lot at Fort DeSoto's North Beach. The natural area borders a bird sanctuary and is part of a tidal pool. When the tide went out, it exposed the snails, according to professional photographer Robert Neff.

However, it is also possible the snails also came to the shallow waters because they found food on a beach that was washed up by recent hurricanes, according to Lucy McGinnis, a former research assistant from the Georgia Sea Turtle Center.

The video was filmed on November 11.