Mine don’t either. When there was another lock down in the Netherlands over a year ago. I locked them ip initially because it was said that this HPAI was even more contagious and killing than the one we had before.
But after the winter had passed I got fed up with the law to keep my chickens in the run. It’s just not healthy to keep them locked up all the time.
And the stupid factory farmers who are the cause of this problem do everything to prevent the vaccination program because they can’t export the chicken meat anymore after the chickens are vaccinated. Most eggs and chickens in my country are for export.
In the meantime many milions of chickens are gassed/killed bc of the bird flu. And there are no free range chickens anymore that can go to the meadows
Some farmers even keep chickens on plastic gras nowadays under a roof, because it look better.