Last year I had my own time with rats... they were only in the turkey barn because I am fortunate. My cats killed and ate the nasty things. I first had my suspicions when I started seeing holes in the floor of the turkey building (the only building that they cats couldn't get into). I was trying to figure out what made the holes but never saw the critters all winter. Then came spring... my first real proof was a half eaten rat in the barn where the cats were. Then one night, I walked into the turkey house to feed and came face to face with about a dozen of the nasty things and they just stared at me. They didn't even try to hide.
I tried mixing up a dough with flour, peanut butter, and sugar and feeding it to them long enough for them to see that they liked it, then I mixed in a lot of yeast with it. My theory was that they would eat it, the yeast would produce gas, and they would explode. It didn't work. So many nights I was out there with a pellet gun and a flashlight, waiting...
I installed a solar light so that I didn't have to use the flashlight. There were nights where I got six in one night. I still had the flashlight, so I could look down the holes, see a nose, and shoot. A bit creepy, having my face about a foot away from the hole, peering in. One night I shot one, it was bleeding and charged out of the hold right at me. From your description, I am sure you know how I jumped around screeching. It was 2 AM, the birds were sleeping. I reloaded as I ran and managed to shoot it again. And I will add that DH and DS never went out there. I think they are afraid of rats!
I don't know how many I shot total, then it started raining - for days - and the roof leaked. The floor turned into a mud pit so I had to move the turkeys and I think the few remaining rats got flooded out and left. I haven't seen them since, but from what I understand if you have rats there won't be mice. Apparently mice won't live in the same territory. I haven't seen any mice so either my barn cats and house cats are doing a great job, or....