I don't want to knock the weasel, because it saves on grain storage by eating all those mice and rats, but it will go through the hidden mouse hole in your coop wall and kill everything it can grab. Last week I lost five hens. I thought it was a coon because I wasn't closing my coop up at night and the window was forced open (it was the wind I now know, faulty chain hook). I closed up the coop, knowing the coon would be back, turned off the light and went to bed. The next morning, five more dead, including three of my sweethearts I forced into the coop the night before. The only gap I could find was a 1 1/2 inch gap in the human entrance door. I pinned it tight, set a live trap and left the light on at night, trying to figure out how something squeezed under the door gap. Yesterday, I investigated deeper and found a mouse hole on the outside of my coop that led into the wall beneath insulation. I pulled off the internal wall and found weasel scat with feathers in it. It was going through the wall outside, and ending up right on the roost, killing everything that slept on it. Thank goodness I have been leaving the light on! Lesson learned: No gaps for mice and leave the light on!