So, I've searched the threads and am probably more confused now than before. Here's some history and our major mouse dilemma...
HISTORY: Although we live in an urban area, our property (1/3 acre) backs up to open space on 2 of the 4 borders. Thus, we have all kinds of critters from small to large. Although we had seen a mouse or two on occasion in the garden before we got our hens, they were never a problem, and we also had enough snakes to (I think) keep it under control.
NOW: Mice, mice, mice. Bold mice - in the run in the daytime, sometimes when the hens are even out. They seem to either not notice them or not care. (Same with the bold squirrel we've named "Ben" - he will sit at their feeder munching away while they're sunning themselves in the far end of the run. UGH!) And they've started invading the garden, eating tomatoes right on the vine. (I know this is not squirrels as the squirrels pick the tomatoes and leave them, half-eaten, in the garden walkway. (UGH again!)
COOP/RUN CONSTRUCTION: At the time I thought putting the run directly on the dirt, using the "apron" method to keep more predatory critters out, was the wise choice - so that the girls could dust-bathe and scratch on the dirt floor. But those little rodents are crafty and, unlike a fox, have tunnels starting yards away from the run (we see them along the house and out along a retaining wall) and the run just seems to be an exit on their underground highway.
WHAT I'VE ALREADY DONE: The food supply is kept locked up in a metal trash can. We bring the food from their run/coop in at dusk, sometimes sooner. Now that it's cold, we close the coop up at the same time. Last year there was a bed of babies in the coop when I cleaned it out in the spring and the girls thought that was the best treat EVER - made me sick to my stomach and freaked me out thinking of all the nastiness that my poor hens had been living in and I didn't even know it! So this year I've been extra vigilant about stirring up their bedding almost every day and spreading non-mouse treats all over the floor of the coop to keep the girls digging (meal-worms, lettuce scraps - I know, mice will eat anything, but it doesn't seem like these things attract the buggers so much). Bonus, it heats up the coop in the cold. :)
Also, I've set traps - lots of them. I only get about a 50% rate of return - they either set it off early and eat the stuff after it's snapped OR the trap doesn't spring and they just eat and leave. Plus, I'm thinking that I'm not even making a dent in the problem this way... there are more and more little holes each and every day. I'm sure there are hundreds of them lurking beneath us. Thank heavens there are none in the house... yet...
NOW WHAT? The only thing I have left to do as far as I can see is poison. Not my first choice, as I don't want to harm anything but the mice. (Yeah, not even Ben...) Two problems with this as far as I can tell.
1.) When they all die - the smell of hundreds of dead mice. Maybe not so bad right now that the temps are consistently below freezing, but when it warms up... um... can't imagine!
2.) What if a mouse mama-to-be has set up a spot in the coop that we (me and the chickens) haven't gotten to somehow already... and she takes the "treat" back to her "spot"... and the chickens get into it? It would kill me if they got into poison somehow. I am certain I can keep it far from them when I bait the mice BUT what if... what are the chances???
It really is bad enough that I've thought of calling a pest-control company - but are they gonna do the same thing I would but charge me an arm and a leg?
Thoughts, please... anyone...