There is a pack rat storing all kinds of stuff in my chickens nestbox, snap traps are not an option for my dangerously curious chickens, and I'm scared that the rat might be a danger to chicks what can I DO?!?!
I use bait boxes (tamper proof) and chunx bait. Strong enough to take care of all R.O.U.S's and safe enough to put right in the run. Unlike pellets that can be strewn about the chunx is chewed off so stays in their cheeks. Take back to brood and before you know your rodent problem is gone. It's what I use from the get go so no colony of pests from mice to squirrels take up housing in the area of the chickens or my house.
You'll want to remove the "nest" they are building in your coop a.s.a.p., make sure you removed all of them then put out a bait box. I'd put one on side of house too. In fall pests start to put up residence so it's a good idea to stop them before they get in.
Personally I think bait boxes should be mentioned in all chicken 101 books and lists of beginners materials. Once chipmunks, rats or mice start a colony it's a nightmare. See more than three holes or rats in the daytime and you are already overrun.