We had a rat problem in our coop. They would build little nests with big piles of corn in the nesting boxes. Rats can kill and eat chickens and their eggs. But what really concerned me was the vast amount of tunnels under the coop. We poured a concrete floor in the coop, and there were enough tunnels to make the coop fall in! We tried drowning them, that didn't work. We would put the ducks somewhere else and let the dog at it. They just hid. We left the cats in there at night. That did eventually catch two babies. They would wait until the door would shut at night and then come out. They could fit through a crack in the back door. Finally, Arlis bought some rat shot, and used his rifle with the scope and a flashlight, and got the momma in one shot. And this was a big momma. There's a reason the cats never got her.
Immediately after shooting her, Boy ran to get her...and finish her off.
Knight, on the other hand, sprang into action and killed another baby. Then he spent a good while prowling the grounds in search.
I hope that was all of them! We still keep Delta and her brood safe in a kennel at night until we're sure. Our neighbor said he lost several to rats just a few weeks ago...oh dear.