Hello, I realize that your question was posted a long time ago, but perhaps you may see this. How is your sparrow doing? I also have a pet rescued (handicapped with a crooked leg) English house sparrow. I rescued him after he fell 15 feet from the eve of a restaurant roof onto broiling hot pavement and he was dehydrated, flailing about and had a badly injured leg. He was just sprouting pin feathers, approximately a week old at the time, judging from online photos of baby sparrow development. He is now, in September, three months old and is finally losing his juvenile feathers and getting his black bib and more colorful adult feathers so I can clearly see that my little girl is actually a little boy. (cute as a button!) Sparrows molt every end of August /September, at least in the new york area. When molting and getting new pinfeathers, they get a bit scruffy, constantly preen and even have a bit of trouble flying and instinctively like to lay low for fear of predators until their new feathers come in. In the wild, this is a precarious time for them as the reduced ability to fly puts them at great risk from cats and hawks. even in captivity where they are safe from such predators, they still maintain a bit of instinctive skittishness . I think, like teething, sprouting new feathers particularly primary flight feathers, may make them a bit uncomfortable for a few days. My sparrow pulls at the old, worn feathers cleans the sheaths off of the new, and smooths the new ones by running them through his beak. The first old feather my sparrow pulled out, he brought to me like a little gift, or as if to ask me, what's this all about? It is possible that your sparrow has mites if he was fully feathered fledgling when you found him. A vet or someone on this site could best answer your question about ridding him of them. But in my own case, my sparrow simply loves to preen, and when bathing and toweling, I have never seen evidence of mites. He just likes to preen and explore his vocal abilities, sometimes making sounds I have never heard from House Sparrows in my yard, or even on the Cornell ornithology bird sounds web site. (He warbles like a parakeet when I run water in the sink to wash dishes.) He fluffs up a lot, especially when the temperature is cool. He also obtains oil from a gland near his tail which he smooths through his feathers to condition them. I am finding a lot of information about sparrow/bird behavior in books and online and my little sparrow teaches me something new every day. I hope your sparrow is doing fine and that you are a happy couple! I'm not sure if it is permissible on this site to recommend a wonderful and useful book or two which you might want to read, but I will: J. Denis Summers-Smith ON SPARROWS AND MAN (and THE HOUSE SPARROW, but this second book is out of print and pricy), SPARROW by Kim Todd; PROVIDENCE OF A SPARROW by Chris Chester; BIRD IN MY HAND by Loraine Hodgkinson.