Story highlights Giant African snails are menacing Florida's Miami-Dade County, say agriculture officials

They can grow as big as rats and could carry a potentially deadly parasite

Driving over their sharps shells can puncture car tires, experts say

Experts warn against handling them and suggest calling local agriculture agency

Florida, already threatened with sinkholes, now has a new terror: rat-sized, tire-puncturing snails.

Sounding like something out of a 1950s B-movie, these giant African land snails eat their way through some surprising stuff, including stucco, plastic recycling bins, signs and more than 500 species of plants, says the Florida Department of Agriculture.

Their calcium shells bear pointy edges that are sharp enough to blow out tires of vehicles that run over them.

Agriculture Department spokeswoman Denise Feiber says the menacing creatures also carry a human parasite called rat lungworm, which is a form of meningitis and potentially deadly.

So far, no human cases have been reported in Florida, Feiber says. But some giant African land snails that have been captured in the state have carried the parasite.

The snails are isolated to the Miami-Dade County area, says Feiber. Experts don't know exactly how they were first introduced to the United States. It's thought they may have hitched rides aboard incoming travelers' luggage. Or some of them may have been intentionally carried into the country as pets -- and then released.

The snails have another trait in common with rats: They can multiply very rapidly -- and grow to adulthood in a year, Feiber says. The snails can produce up to 1,200 eggs per year, and they can live up to nine years.

Since agriculture officials first discovered the snail invasion in 2011, trappers have collected more than 117,000. Officials are hoping to prevent a worst-case scenario, where the snails would threaten Florida crops.

Some countries, such as Ecuador and Barbados, have run out of resources to fight these critters, Feiber said.