Page #56: Won't Die In The House
I'm not a fan of poisoning animals, even home invaders. :( (And rats are adorable besides)
Anyway! Rough on Rats (the actual thing) was an old arsenic product people used to use for "vermin", and it featured in one of the "Ruthless Rhymes(for Heartless Homes!)" by Harry Graham, where the perpetually ill-behaved "Little Willie" often met is (sometimes well deserved) ill fate. Which is how I heard of it, even if I decided to go for a different spelling, as I often do with products in the comic. I didn't even look up the actual product until a moment ago and was amused to see it also had a belly-up rat illustration on it! He wasn't holding up a lily though.
Good thing Menu didn't say he thought that skull and crossbones meant it was a Pi-rat! :D