Slugs - A Nasty Joke by Gaia, or What?

Slugs - the invertebrate kind, not the leaden ones, or the bipedal ones.

I was visiting some friends in the almost-countryside over the weekend, and late at night, when it gets cool and dark, their lawn and deck get overrun by mobile dog turds.

I mean, Ewwwww. Other than being totally gross, and leaving that indestructible slime all over everything, what is the point of slugs??

AND, I had the misfortune to see two of them having sex. At least I think it was sex. I don't know. The science nerd part of my brain was totally fascinated, but the rest of my brain was completely grossed out.

I'm calling slugs one of Mother Nature's Little Pranks, and she wants to see who gets the joke.