Nasty Delaware won't let anyone else in the coop at night.

[DIYgirl]

She won't let the other chickens in the coop at night. Should I just have her for dinner?

 

[GitaBooks]

You could try separating her into another area for a few days and then reintroducing her, so her position in the pecking order changes. If she is still aggressive, then it would be best to get rid of her (Delawares are good meat birds).

Best of luck!