While slugs can contain parasites that are potentially harmful to the health of humans, they are rarely if ever poisonous. Slugs are invertebrates that are attracted to moist climates, such as those found in the Pacific Northwest.
Slugs spend the majority of their lifetimes eating. They eat many things including algae, animal feces, plants, insects, worms, other slugs and lichen. One slug can eat its own body weight in food several times each day, which makes them extremely harmful in gardens. Slugs contain both male and female organs, which allows them to reproduce quickly once their reproductive organs have matured and when there is more than one slug in an area.