Irma has it figured out. She's a bona fide, egg-laying member of the "Production Red" hen sorority and she knows her rights.
This is really remarkable when you consider the braincase of your average barnyard chicken is wedged between some feathers and those big expressionless eyes and has about the same capacity for rational thought as that of an amoeba. But somehow this hen of mine has figured it out.
The sunlight triggers it, I believe. Sequential logic.