Have a hen that has been a lot less active. She has not been laying in a number of weeks now. She almost acts like she's depressed. Even when I let her out to free range she may eat a little grass and dig for a few bugs for just a few minutes then starts just standing around while my other two hens are active and scratching or taking dust baths. This has been going on now for at least 2 weeks, maybe more. It was suggested she may either have mites or worms but when I check for mites I can't see anything moving on her. I do see some dandruff' type stuff on her feathers. She seems to scratch now and then. Have dusted her several times w/DE and put it inside her coop. She had really gotten into the mealy worms that I bought for her and has eaten a little of her laying feed but very little and seems to be eating less of the worms. She just lays around or stands around most of the time and when I think she's getting worse I look out and she's scratching actively. No other symptoms, no respiratory issues. I just don't know. She lives in a coop by herself because the other 2 girls have brought blood before on her so I'm afraid to keep them together. Should I go ahead and treat her for mites and deworm? I just don't know what else to do for her. I'm afraid I'm going to come out one day and she'll be dead. Thanks for any advice!