I've experienced no problems feeding them these snails that came in with potted plants and established themselves along the walls of my house. But I break the shell and peel it off first. Make sure you don't get them from an area where slug poison/bait is used. Slugs eat nutritious vegetation high in iron and for some plants, calcium. Gut loading them with leafy greens and veggies is a good way to make them more nutritious.