We have a black Australorp hen that was egg bound when we got her. Yes we've tried the warm water bath, gently massaging her area, a little olive oil in a syringe and even reaching into her vent in the hope that the egg will come out. No dice. It's fine since our birds are more pets than anything (because anything that is this expensive has got to be a pet) and we don't mind that she'll never lay any eggs.
Egg binding is not a permanent condition, nor does it cause infertility. If the egg stayed stuck she would die, that's all there is to it. Most die within days, but some last over a week. How long have you had her?
All this makes me think she possibly wasn't egg bound, but had similar symptoms. Certainly it sounds like a safe bet that she has reproductive issues. Perhaps egg peritonitis, internal laying, reproductive tract tumors, all of that's very common and can produce very similar symptoms to egg binding. Could even be her bowels, or stomach, not her reproductive tract, that's having issues.
The odd thing is that she has taken to sleeping in the nesting box on any egg that the others lay in there. At first I thought she was just sleeping in there to get away from the others, well last night I went to shoo her out of there and she about killed me. This morning the same thing. She refuses to leave that nest without putting up one heck of a fight. My wife has told me that during the day the hen only comes out a few times to eat and drink. If it's colder outside she stays in longer.
Can an egg bound hen become broody? If so will she actually hatch the eggs and take care of the chicks?
Egg bound hens die, not brood. Sleeping on the nest is common for unwell birds, it's actually a fairly reliable sign in birds that once perched normally. Many hens have sufficient instinct to prompt them to nestle on eggs whether broody or not, too, just because she habitually chooses to sleep on eggs doesn't mean she's broody at all.
Either she's not egg bound, or something else is up. If it was pitch black when she attacked you, that may be because some birds lash out extremely viciously at nighttime at anything that moves.
Her aggression is quite strange, and if her breast is not completely bare, I would think she possibly has endocrine issues due to something like polycystic ovary syndrome, which can mimic some common symptoms of eggbinding. Excess aggression can stem from hormonal imbalances caused by tumors on the gonads of either gender.
Broody hens do not typically budge from the nest, they don't launch into attacks except in a minority of cases, and those ones needless to say often are not great mothers, since attacking is more of a priority to them than sitting tight to protect the eggs or young. Such hens tend to trample and cripple babies and scatter and break eggs.
Depending on how long you've had her, and whether or not her breast has lost its feathering (you'll have to feel her up to determine that one, lol, since the side feathers cover it so you can't tell by sight alone) she may not be eggbound at all.
Illness or injury typically does provoke rapid attempts to breed, it's like a last minute effort to pass on their genes triggered by a near miss or life threatening condition. Quite often it's the unwell that breed the most, healthier animals tend to take their time and pick prime conditions to breed in only.
Best wishes.
