I agree w
@nuthatched
It could be their diet.
It could also be that they have other issues...
Personally, I would make sure that:
They have a quality and balanced diet, that doesn’t have to be a ‘name brand’ but does need to be a quality feed that includes what your birds need
Oyster shell and grit, offered all the time and separate from their feed
Perhaps some probiotics, esp if you have had chickens before and this batch seems more stinky....
Watch for any bloody/ odd stools, or consider taking a few stool samples to a vet to rule out any parasites if you have a concern about that
....chickens are stinky in general, more or less so, depending in large part on their feed, size of your coop/ run, and overall health of your flock.
If you feel like you have a problem, please tell us more about your experience, your setup, and anything else that might be helpful so we have a bit more to go on
