According to the Royal Horticultural Society, certain bird species eat slugs as well as slug eggs, so it is important for gardeners to encourage birds in their gardens. Raking over soil and removing debris from the garden during colder months allows birds to easily locate slug eggs.
Gardeners can attract birds to their gardens by placing melon rinds or lemon peels in the soil just prior to sundown. Slugs are naturally drawn to melon seeds and use the moist fruit peels as shelter. Turning the peels over once the sun rises allows the birds to smell the fruit and target the slugs.