I had 11 chick that I got at the feed store being raised by a broody hen. I let them free range during the day and pen them up at night. Long story short I went out today to one chick and mama. Mama bristled up and went into defense mode. That is when I notice Mr weasel under a shelving unit. I opened up the coop and gave him 8 hours to escape. Long story short he did not take advantage of my generosity. He must have got in during the day when the coop was open and laid in wait for them at night. Things were 100% when I locked then up at dusk.