Tools of the trade.
I needed a way to make the scorpion kill itself. The story of the scorpion and the frog came to mind, but the odds of finding a frog were slim. Besides, I have nothing against frogs.
Since I couldn't find a unique way to make the scorpion kill itself, I decided to enact ex-post-facto legislation dictating military action on any scorpion trespasser. Therefore by creeping into my bathroom the creepy little bug signed his own death warrant. So when I kill it I can claim that he brought it upon himself (or herself).
And what military action isn't complete without something getting blown up?
Behold, the M90 firecracker!