Miami-Dade County officials estimate they have captured more than 120,000 of the snails since the Florida Department of Agriculture first discovered the current outbreak 18 months ago.
Department workers found "massive amounts of these snails at every property we visited," spokesman Mark Fagan told ABC News.
"We have a staff of 50 that's dedicated to nothing but snail hunting," he said.
In addition to carrying a parasite that can cause meningitis in humans, they represent a threat to the state's food supply, Fagan said.
"They eat 500 different plants," he said.
The giant African land snails first came to South Florida in the 1940s as overseas military equipment returned home, Fagan said, and even today "they're hitchhiking on cargo."
The snails, whose shells can grow to 6 inches, can produce 100 eggs per month and live more than eight years, experts said.
"It's a perfect environment for them here in South Florida," state entomologist Ian Stock said.