Ok I just had to manually dust bathe all 12 of my chickens. They aren't doing it on their own! They're run is all grass so I have a litter box in there filled with dusty sandlike dirt. I've noticed them out laying in the run but its not really dust bathing. I looked under their feathers earlier and saw mites so I said enough and put them in the dust bath myself. They didn't mind it but all they ever do is walk over the dirt in the box and then jump out. Any suggestion? There's 6 EEs that's 2 months old and 6 cochins that are 3 months old.