Help! My chicken won't come out of the coop!

If she's staying on the nest box my guess would be that you have a little broody on your hands.

Yup, it sure sounds like she's gone broody.   Does she puff up and growl at you when you reach toward her?  Most broodies do that but not all.

Does she spend the night in the nest boxes too?  If so, you've probably got yourself a broody!  Take the eggs away from her frequently to discourage her - unless you WANT her to sit on them.  Eventually she'll get over it.  Lots of people on BYC have advice for breaking a broody.  For us, it's just wait till it passes.  Took about 3 weeks last time.

Chickens go broody to hatch eggs and it seems to be contagious, the other chickens might follow.  I have had a silly hen go broody; it refused to sit on eggs, it just wouldn't leave, even when I tossed it out 15 times a day.  If you want to hatch some eggs, just give her a few fertile eggs, and she'll do all the work.  I you want it to stop going broody, confine it in a small area with no nest box.  It will eventually get the picture.

Wow!  Can I sympathize with your broody hen problem!  I have 6 hens - they free range in our urban yard only at the end of each day.  So, two days ago we started finding only 2 eggs when we had been getting 5 each day.  One of the girls is still upset about getting and impacted crop last month.  One of the Buff Orpingtons has taken up residence in a nest box and growled at my 9 year old when he tried to get eggs.  Last night my husband tried to block the entrance with some cardboard stapled over the opening, but she had found a way in again this morning!  Through a 3 inch gap!  So, like you, I wonder if her broodiness is contagious.  Is she discouraging others from laying in the boxes?  We have had the lights on a timer for weeks - it comes on at 5a.m.  Do we persist in blocking her box access or do we just let it ride?

Ummmmm, because she's a cochin?   Give the girl some fertile eggs, cochins make great mothers!

Same thing with my Silkie mix. Where do I get the fertile eggs from? (no roo.)

1 of my cochins went broody . The little black hen , she wouldn't get off the nest all summer . She was loosing weight . I took eggs from her , I even locked the chicken house door all day for a week to make her eat . The moment the door was opened she was right back on the nest . I finally gave up . I put her in an isolation cage with food and water not six inches away and let her sit a clutch of eggs . She would hatch anyones eggs . I took one egg from about 7 hens , she hatched all of them . She raised the chicks . That seems to satisfy her . She finally quit setting about a month ago . I know this spring I'll have to do the same because she will never abandon her nest . She even faced down a rat snake and drove it off . The wierd thing is she corned it and pecked it to death . She's a good momma and a great snake killer . I thought chickens were afraid of snakes , not this little black hen .