I had set out poison for ground squirrels getting in my garden by pouring the bait directly into the hole and covering the hole up. I went to let my girls out one morning and missed a dead field mouse that had managed to make it to the grass beside their coop. They scooped it up, playing keep-away and tug-o-war with the nasty thing. I had to chase them down and take it away (with my hands, because that was NOT something I anticipated having to do!) before they ate it since it had been poisoned. I'm sure I was a sight to see chasing down chickens with a mouse first thing in the morning. I'm lucky they didn't manage to gulp it down. I was surprised that it made it that far over from where I had poisoned the hole! The ground squirrels always just land very close to their hole opening.
ETA: If it had been a live mouse, I would've let them eat it. I only took it away so they wouldn't be poisoned by it.