They’re every gardener’s nightmare: giant snails the size of a man’s hand that eat up everything in sight, leaving only a slimy trail. South Florida is battling an invasion of the African species, one gross gastropod at a time. The snails hibernate in Florida’s winter, but come out with the rains. Suzi, an agricultural inspector, can find hundreds after a storm. And each of the pests can lay 1,200 eggs a year.