Some of the words I heard when the kids & I discovered two slugs 'going at it' on the back of our house last night!
They were hanging from a foot-long piece of goop, which was attached from above. An organ was protruding from their heads(the blue swirly thing), it was pulsing as they did their deed.
We looked it up online right away to find out they are hermaphrodites (no surprise, as they looked identical & so did their organs!)
When finished, their organs retracted into the side of their heads & they "slugged" off.
It was one of the strangest things I have ever witnessed...
I will be uploading a lengthy video of the ACT on my youtube.com page... http://youtube.com/user/philkellyk