I'm not a science teacher but I find them interesting.
Actually when I was a kid, I had pet garden snails. They where easy to care for and kind of cute with their giant eye stalks. Not exactly slugs I know but close!
Slugs are a part of the natural ecosystem and like all other living things they have a role to play. If you love nature, you could look at slugs as a part of that and love them for that reason, maybe even if you think they are not the most attractive animals around.