Slugs in Wood Preservative

[Zebra]

Going to use up some old wood preservative on making the shed, I found it full of mushy lumpy bits. Curious, I sieved them out, and extracted quite a quantity of what I can only think are slug carcasses.
Firstly, what on earth were the silly critters thinking, going in there? Secondly, how on earth did they get in, with the lid on? Thirdly, will a coating of dead slug impair or improve the longevity of my shed?

 

[Andys]

Are you quite sure you hadn't accidentally bought slug preservative?

 

[Zebra]

Giraffe reckons that they might have got in there to get high, perhaps with the help of other slugs who screwed the lid back on afterwards.
Hang on.... what if it was murder?!

 

[skier-hughes]

I don't know what all the fuss is about, it quite clearly says interior on the tin.