Look for the slime. That's the message from the Florida Department of Agriculture and Consumer Services, which is asking Floridians to look out for the tell-tale slime trails of the nastiest invasive species to hit the state in recent years: the giant African land snail.

These massive, rat-sized snails first showed up in Miami-Dade County in 2011 and have since spread like slimy wildfire. According to a report from Reuters, well over 115,000 of the snails have been caught to date and 1,000 more are being caught every week. And with Florida's rainy season just a few weeks away, those numbers are likely to soar in the coming months. The snails are prodigious breeders, laying more than 1,000 eggs, each of which hatches in just 11 days.

Giant African land snails (Lissachatina fulica) are illegal in in the United States, although they are also popular pets in many places, believe it or not. It's uncertain how they got loose into the wild in Florida — they could have been accidentally released or stowed away in cargo — but the danger they pose is clear. They eat more than 500 plant species and devour stucco and plaster, chomping their way through walls and even concrete. They use the calcium from stucco to form their shells, which are reportedly so tough that they can blow out the tires of any cars that drive over them.

Beyond the danger to agriculture and Florida's ecosystems, the snails could also have in impact on human health. They can carry a parasitic nematode that can lead to meningitis in humans, although that has not been seen in Florida. They also carry diseases that can affect many plant species.

This isn't the first time that Florida has been invaded by giant African land snails, although the current invasion is already far worse than the one that started in 1966 when three snails were released into a Miami woman's garden. Those initial three snails multiplied to a population of 17,000 which Florida spent $1 million and 10 years to eliminate. According to the Global Invasive Species Database, that infestation would have cost the state millions of dollars annually in lost agricultural productivity if had not been stopped.

The best method to control these pests seems to be tracking them down and picking them up before destroying them. Some countries control them with poison or flamethrowers, although each method comes with its own set of added dangers. Letting the snails die without collecting the bodies can also pose a problem, according to the Global Invasive Species Database, which says the snails' decaying bodies release calcium carbonate from their shells, which "neutralizes acid soils, altering soil properties and the types of plants that can grow in the soil" — and let's not forget the bad smell associated with dead snails.

Florida is asking anyone who thinks they have spotted a giant African land snail to call a special hotline (888-397-1517) so personnel can investigate and collect the slimy invaders before they cause too much damage.

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