The Scam of the Mysterious Adventurers

I have long since come to the conclusion that the "rat menace" is actually an elaborate scheme to defraud the town of its money. The warning signs are all there, so clear as day that I wonder why anyone else hasn't caught on yet.

First, these "adventurers" that mysteriously appear out of nowhere, dressed in exactly the same attire, all so coincidentally mute. They'll approach me to be "briefed" on the rat problem, but many simply skip through my introduction as if they've heard it before. I suppose they must have, for immediately, without even doing any prior research, they know where to head in order to hunt rats.

It's almost as if they have some magic arrow that points them in the correct direction.

Then, as quickly as they leave, they'll return with evidence of their successful eradication campaign. Interestingly, the proof is always 50 rat tails, not one more, not one less. Not rat pelts, nor complete carcasses, always rat tails. And once they collect the reward, they'll never appear before me ever again, even though the bounty still remains.

It's clearly a scam, isn't it? For all we know, they could literally be farming rats somewhere right outside of town.

The joke's on them, though. I've managed to convince these adventurers to accept most of their bounty in the form of an entirely imaginary reward. It's not money, or weapons, or any real or physical material. Yet for some reason, they all seem exceptionally delighted to be informed that they have received 'XP'...