We introduced ducks as slug eaters. Our first thought was Pekin ducks which lay lots of eggs. However, they are large and we didn't know how much damage they may make. So we opted for white call ducks which are smaller. They don't lay eggs to eat, but they did raise a pair of duckings, which was very cute. They didn't make much damage to the garden and they continually sift through the soil for bugs and eggs. They do eat whole slugs as well. They don't eliminate the slug problem but definitely seem to help.