Are rats or mice living in this container? I know we have a rat problem but I don't understand why they would live in this.... Should I turn it out and see if my chickens want some yummy live snacks?
If you truly think that's rats, I would seal the top with a big screen, then take that far away from the coop as in a few miles away, and dump it out. If you want to kill whatever's in there, just pour gasoline in it with the screen on. That should do it.
If you tip that upside down and let whatever's in there out, they'll likely get away and build a home somewhere else.