I am engaged in an ongoing war with a family of chipmunks that has taken up residence in a narrow strip of ground between my house and our outdoor fish pond. They are perilously close to burrowing through the pond liner, unleashing a thousand gallons of water against the base of my house.
While the chipmunks and I are evenly matched intellectually, I am thus far in the lead, 2-0. But my battle against the chipmunks led me to this scenario:
Imagine that the doorbell rings, and you go to the front door to discover an unexpected package from Amazon. The box is strangely wrapped, and some of the words are misspelled, but you can see that it's stuffed full of money -- some of the cash is leaking out of rips in the cardboard. So you lean over to pick up the box and... thwack! Revenge of the chipmunks.
I am pretty sure I've seen the scenario play out in some science fiction story or another, but I cannot quite place it. Maybe a Fredric Brown short story? It's certainly his style. In the meantime I shall be very suspicious of any unsolicited packages I receive.