In my quest to find out about the defense mechanisms of slugs, I came across lots and lots of research papers on Sea Slugs. I now want to withdraw my comment about slugs belonging in God’s reject bin. This is a sweeping generalisation and the reject bin should just be open for the common garden slug.

Sea Slugs are WICKED! have a look on here:
http://www.hawaiisfishes.com/inverts/slugs/neatslugs.htm

I also found an interesting website by someone who has come up with the terrifying idea of flying slugs! Check out his website which discusses how flying slugs would affect the economy, technology and religion…. http://www.belch.com/?page_id=26