Leopard Slug on the Move

Slugs are observed in the Colvin Run Habitat about once a month - usually in dark, cool spots - but it is not too uncommon to find them traveling across the slate walkways or even the mid-day mulch (provided its in the shade).
Slugs are mollusks (think of them as snails without shells). The two slugs pictured here are leopard slugs, named because of their coloring.
Click on the photos to see an enlarged view. Slugs produce two types of mucus to help in movement. In the first photo, you'll notice the thin, watery mucus produced underneath them to assist in general movement. In the third photo, you see a thicker, fiber mucus coming for the rear of the slug.