In the 1960s, a boy vacationing with his family in Hawaii pocketed a few giant African land snails (Lissachatina fulica), a mollusk that grows to a foot long and a full pound. Hawaii had been battling the pest, and so too would Florida, where the boy returned with his new friends. Once home, he quickly grew bored of the snails and handed them over to his grandmother, who set them free in her backyard.
What ensued was an invasion by rapidly reproducing critters that have over the last century spread out of their native East Africa into tropical climes all over the world, from Asia to South America, as stowaways on ships or as pets brought home by people with a thing for snails. In Florida, eradication took seven years. Other places, like Brazil, have not been so lucky in their efforts.
You see, the giant African land snail is a hermaphroditic love machine. “Snails have female bits and male bits,” explained biologist Robert Cowie of the University of Hawaii, “a single pore, through which if you’re acting as a male, a penis extrudes, or if you’re acting as a female, through which the other snail puts its penis in. And in some cases they can do it reciprocally.”
Thus the giant snail never meets another snail it can’t get busy with. Once fertilized, the snail will bury several hundred eggs a few inches below ground, and because of the incredible size of the species, the young will emerge far larger than native varieties, making them that much more resistant to predation.
Alas, four decades after evicting this enormous, fecund snail, Florida finds itself overrun once again. The creature was reintroduced here in 2011, and this time, according to Cowie, it may well be “bizarre, voodoo-like religious proceedings” to blame. The snail’s slime, he says, is coveted in certain South American rituals, and practitioners may have released the giant snails into their Miami-area backyards, hoping they’d breed freely.
The USDA and U.S. District Attorney’s Office are investigating this. It probably doesn’t help the ritualists’ case, though, that the year before the current outbreak, authorities questioned a Florida man said to have convinced his followers to drink the fluid from live giant African land snails, which he sliced open before squeezing the slime into their mouths. If you can believe it, the victims fell violently ill — ironic, what with this being a healing ritual.
Anyway, if it was indeed the practitioners who released the snails so they (the snails, not the practitioners) could multiply rapidly, it worked. Big time. Florida agriculture officials have collected 137,000 giant snails in just over two years. Compare that to the relatively few 17,000 collected in the first eradication in the 1960s, and you soon see the magnitude of this problem.
Today, Miami is simply overrun with the things. Not only do the giant snails chow on some 500 economically important plants in the area, they’re devouring houses. It seems they have a taste for stucco, which contains precious calcium. Without a ready supply of the stuff to fuel their amazing growth, they’ll simply turn on each other — at least in captivity.
A long time ago I had some African snails in the lab, in an aquarium-type tank,” said Cowie, “and apparently I wasn’t providing a sufficient source of calcium, and they would just eat each other’s shells. These snails produce big shells, they need a lot of calcium, and a lot of people these days when they keep snails they’ll put a bit of cattle bone in the terrarium for the snails to chew on, just to get the calcium.”
And because I know you were wondering: Yes, you can eat giant African land snails. But cook them well. I mean really well. Just boil them for a month. Grill them with napalm if you have it. Because like many snails and semi-slugs, this species carries the deadly rat lungworm.
As its name suggests, the parasite attacks rats, which pass the larvae in their feces. Snails that eat this waste are infected, as are folks who eat the snails. In humans, the larvae attack the brain, leading to meningitis and often a pretty horrible death. This has been documented as a particular problem in China, where people may not be cooking giant snails sufficiently.
But for all the folks who cook their giant snails properly, still others ingest them accidentally. All manner of critters could very easily end up in your Caesar salad, for instance, since cooks don’t always peel apart the lettuce before chopping it. “And it could just as well be a little baby African snail,” said Cowie. “OK, it’s a bit crunchy, but so is the lettuce a bit crunchy, and you’d never know. So that’s the way people generally get infected in places where they don’t habitually eat raw snails.”
With such health risks combined with the damage to agriculture and the snails just being a public menace — with shells so big and sharp that they can puncture tires that run them over, for instance — Florida is sinking millions of dollars into its eradication measures. The state has 50 full-time staffers assigned to the project, said Denise Feiber of the Florida Department of Agriculture and Consumer Services, which is leading the effort.
By deploying common over-the-counter snail poison and advertising a hotline residents can call to report sightings, authorities have so far been able to contain the critter to Miami. And no, pouring salt on them is in no way an acceptable option for homeowners. It’s a horrible death. Osmosis pulls the water out of the snail, killing it of dehydration. Just don’t do it. Ever.
But it’s possible, according to Cowie, that the giant snail could well spread to other Gulf states, though luckily they probably can’t tolerate the cooler weather in Georgia and other states farther north (contrary to popular belief, Hotlanta is not in fact always hot — most of the time it’s just Atlanta).
Cowie knows all too well the explosive population growth these things are capable of when left unchecked. In Hawaii, where he lives, the giant African land snail was introduced in the 1930s by Japanese immigrants who wanted to keep them as pets. They have since essentially assumed ecological control, tearing through agriculture and muscling out native species.
In 1950s Hawaii, “there were stories of on a rainy day, when the snails all came out and crawled all over the road,” Cowie said, “the cars would squish them and cars would end up skidding on the squished snail. Dead, crushed snail and slime, sort of all mish-mashed together by the cars. So that was when Hawaii got serious about trying to control them. And we’ve not been successful at controlling them.”