Some problems my chickens have had and how I treated them ~
Mini was born with many problems: she was small and pale, and had pasty butt, button navel, and had bits of shell membrane stuck to her. There was a short spike in temperature a few days before hatching which may have caused her problems. Her brother was born perfectly healthy! She is now nearly grown, and other than still having problems with poo sticking to her butt feathers, is very healthy.
"cut off" and the dark areas around and on her head, as well as the feathers that are glued together, are bits of shell membrane. Though she looked really pitiful, it dropped off as Mini grew and was pretty much gone 10 days later.
"more gobs" is pasty butt. Mini had it on day one, so don't wait to wash any gobs off your chick's butt! It was dark green. The chick's skin is very fragile, so I wet the gob and let it soften a bit. Slowly, it came off.
Here's Mini's butt after it's been cleaned. The dark spots at the bottom is button navel, caused by the navel not being quite fully formed when the chick hatches. I didn't do anything, the spots fell off on their own as Mini grew.

Body Lice on hens
I'm currently treating my hens for lice. I want to use the least-toxic method I can. Meter had patches of lice near her vent and her vent was red and raw. Tap's vent looked ok but she had lots of lice eggs near it. This isn't my chicken, but here's what the lice and their eggs look like (the eggs are the white masses):
I dusted them with sulfur, the kind you get from the garden center for plants, and this killed the adult lice. My hens looked much perkier. As with any dust, wear a dustmask and gloves, and wash any exposed skin afterwards, because any dust can be very drying to your skin and lungs. And I recommend dusting them outside or in a place that you don't mind if it smells mildly of rotten eggs for months! (I first dusted them in our bathroom and it still smells a bit after four months.) I re-dusted them every two weeks, three times in all. It's been four months total and I haven't seen the lice since the first treatment.

Leg Mites
more to come...