I checked under the roost bars last night and didn't see anything crawling.
The weird thing is that the feather loss is so much on their bellies and not nearly as noticeable if at all on their necks where I've heard the molting usually starts. They are about 17-18 months old - so at the age their first molt could occur.
I haven't seen any pin feathers yet.
They seem to be acting normally, and all are taking their usual dust baths.
I did change their layer feed recently, but it is still an 18% protein feed and they all seem to be eating it.
Please help with any advice or suggestions! These girl's are my first chickens and I have never had a molting or mites yet - so very confused and worried!