I have never heard of them either till I started visiting veggie garden sites. my biggest issue is slugs in the pacific north west they grow to a good 6 to 8 inches long and come in three types, black,brown and banana. can burrow up to 6 feet under ground and hibernate over winter. But there is an up side to slugs the banana slug is native and doesn't suck down growing plants it eats dead and decaying plant material so in some ways can aid a garden or compost area. so I don't kill off the good slugs I have placed copper stripping around my raised beds and this has deterred most slugs a few do get threw but not many. ya you haven't lived till you have an 8 inch long slug that looks like a rotten banana stuck to the side of your house.