Chickens will sneeze. however, if they are sneezing alot, for several days, then I would get a little concerned. Are they still active? Do they have visible mucus? Has it been dustier than normal in the past couple of days?Is it normal for chickens to sneeze? I have some sneezing chickens. I started brewing my first batch of FF btw! A tiger? Lol
Thay could just be clearing their sinuses, of perhaps ha\ve a cold. If it continues, and they start acting "sick" you may need to begin treating them.