[jaydee]

Why is it I can keep spraying the same single fly in our kitchen with Mortein, next morning, there his on the bench. Zap him again, flies of like a drunken sailor, get home from the gym, still in the kitchen on fruit in the bowl.
Honestly, I'd be better off throwing the can at him, bloody useless.
I'm sure they've evolved to be immune, it's not the first time, half a can on one fly.