This is totally off topic (well, almost totally), but I wanted to share a new 3rd generation rodenticide I found recently that is specifically created to reduce the risk of secondary poisoning, which can be a huge problem with dogs, cats, and various predator birds. I know not everyone is fond of hawks and owls, but I am a birder as well as a breeder of poultry, and I wrote an article a while back for Backyard Poultry Mag about the nastiness of the second generation rodenticides, after one of our dogs got into a bait and almost died.
So when i found this, I was pretty excited to read about it, and I ordered a pail which came yesterday. Set it up in the main layer coop and a couple of other spots, we'll see how it works. It's called Terad 3, and it also poses a low toxicity to birds, so in theory it won't be an issue for chickens either. Here's the website I got it from:
http://www.domyownpestcontrol.com/terad3-blox-p-1283.html
I'll check back in in about a month and let you know how it's working. (Note, I have no connection to the company that makes it or the website that sells it, I'm just looking forward to using something that will kill mice but not my barn cats.)
It's totally your decision to use this stuff but I've read about something that involves no poisons at all. A 5 gal bucket with something to climb on the outside. Across the top, attach a piece of wood and from that suspend a popsicle on a piece of thin wire and put some very yummy smelling stuff on the popsicle stick. When they smell it and climb up the bucket and jump down to get the goodies, they miss or even if they get it, they can't climb that thin wire and they fall to the bottom of the bucket. At the bottom, there are 3-4 inches of water and they swim around for a while til they can't swim anymore. In the morning, you have lots of animal protein for your birds to chase around with.