I never had issues, then we had a bad flood, and suddenly I was overrun with rats, I think the flood killed and displaced the stray cats that were keeping the rats away. I kept my quail under my deck for 2-3 years and had no issues, but once the rats found their way in, they made themselves at home. An apron didn’t help, I had cinderblocks lining the outside, so they couldn’t even start the dig near the apron, but they still got in. They killed most of the quail and the ones left were mentally unstable and didn’t really lay after the event. The only way I found to keep them out 100% is wrap the whole enclosure in hardware cloth.
I built a large aviary out of a greenhouse frame, and I laid hardware cloth on the ground, wired them to the HC on the walls with no more than 1 inch apart (literally wire connects every other half inch square). Then I put pavers over the HC and put my wood chips over the pavers. I never leave the door open, even though I don’t have any more quail, and my turkeys can handle rats. I’m so afraid of rats getting in my aviary I’m like a maniac about the door and I’m building an airlock chamber because, kids haha.
I have seen the rats climbing the aviary walls to see if the roof is covered with HC too (it is) and once they checked it out and figured out they can’t get in, they have moved on, and I don’t see them running around the yard at night.
The first night after the second big attack on my quail pens, I was kind of bitter and angry. You know in Jurassic park when it’s real quiet and the giant eye of the t-rex opens in the background…. I assume that’s how the rats felt when they showed up for another easy helpless meal of quail and met my angry tom turkey I had put in for the night haha. Sometimes it’s nice to feel karma kicking them back a bit
I know many people don’t mix turkeys and chickens, but I hatched all of mine from eggs so the only illness vector really is contact with wild life and they would experience the same risks alone or together. But my Tom is great at yard protection, I don’t let him out of the aviary, but he watches the whole yard and yells at anything out of place, he doesn’t sleep inside unless it’s raining, he sleeps on top of the shed I have in the aviary, and watches over everyone as they sleep, I’m certain if vermin could get in, he would take care of them. The females usually sleep inside the shed or coop with the chickens, so they aren’t as vigilant as the male, but they come to see the commotion if he sounds the alarm. turkeys make great guardians from small pests in my experience.
), but I did go online to google and did some research on rat behaviour. 
