Why do some of my hens have red bald butts?

[trinitymare]

And will they be fluffy again? Is this molting? stress? broody? sorry if this is in the wrong topic.... they all had fluffy butts just a while ago and they never got dirty as far as I know. It's gross looking....

 

[gritsar]

Without evidence of mites, what I see on the hen to the right of the picture is normal. Comes from laying eggs regularly.

 

[trinitymare]

It did happen when they started laying but the most heavey layers have flufflybutts..... I'll dust them just in case but I have never seen any and I'm pretty good at seeing them...

 

[gritsar]

Best way to check - go into the coop at night with a flashlight. Pick a hen and turn her bottoms up. Look around the vent area for white or black specks, like salt and pepper. Also, check the crevices of the roost and coop corners.
DH warned me before I got chickens that their fluffybutts would go away as they were laying, but it hasn't been that bad. I do have a few girls that look like that one of yours, but I only notice it when she's bottoms up.