I just bought some dusting chemical in the US for my chickens, just to try it out as it seems easier than our method of giving them a bath with anti-lice shampoo. The main ingredient was Pyrethrin. It came in a shaker container similar to scouring cleansers.
Anyway, I was 100% sure I packed it nice and tight in my luggage. Well, when I unpacked at home, it was gone.
It was obviously them. Good thing they didn't touch my other goodies.
Thanks!