In California, the extension service has tried using them as biological controls on slug infested areas, but so far they haven t proven to be very effective. Slugs really are slow, averaging .007 miles per hour when they move. At maximum warp, they can cover about 3 inches per minute. Though the cure may be worse than the disease, slug slime will reduce the sting from nettles. Slugs can stretch out to eleven times their normal length.
Slugs like to stay in cool, dark environments where they are protected from sunlight and predators.
That s why they do so well in ivy and other thick ground cover. Jelly-like and covered with slimy mucous, they dry out quickly in direct sunlight. Lots of creatures, especially birds, snakes, and beetles will eat slugs. Also, ivy provides a great place for their eggs. Laid down in clutches of three or four to forty or fifty, slug eggs are covered with a tough coating of calcium carbonate.