I would add a couple of things...yes, learned the hard way over the years.
If you use snap traps for rodents, always, always, always put them in something like an overturned milk crate so the rodents can get to the traps but the birds cannot...even if the trap is on the other side of the yard, by the wood pile, far away from the chicken's fenced run. Yup...my prettiest little game bantam flew over the divider fence, found the trap, and I found her quite dead. Sniff.
Which leads to wing clipping. Stay up on clipping those wings of your flyers...it saves a lot of head ache.
And finally, with every new hatch, do the fence crawl in the grow out run to check for new holes that rodents may have created by digging under or in between.
I had a fretful afternoon one day when a chick had found a rodent hole in the wood slats/bottom footer of our back to back chain link with our neighbor's property. She managed to get stuck BETWEEN the two fences. It was several hours of coaxing and hunting with momma broody frantically calling. We finally found the little dear (who would go silent whenever we got close) and managed to flush her out to where we could catch her. Fortunately it was warm weather so the worse she had was some stress. In cold weather, she would have not survived.
So I do the fence crawl in my broody run every hatch now. Never assume a tight fence is still tight.
Good thread and good suggestions.
LofMc