Mary Ann, I hate to be the barer of bad news, but chickens are in bed by sun down, and get up at sun up. Besides, they are all tired out from weeding all day and eating iris borers.
You will need to train some nocturnal animal to guard at night. Maybe a ninja guard cat? My Pit bulls sleep all day and guard my irises all night.
Yup, we got caught on the chair again!