All right, this one's hard. My wife has a cat-shaped object named Foosball. She's a deaf albino Manx, and she's partially feral. She shreds, yowls, steals food, and practically ignores the litterbox. Also, the worst and most frequent gas of any animal I've ever seen. We saved her from a gas station parking lot where she was just barely dodging cars (can't hear them, after all) and have for close to a year, been trying to get her to act decent. She had a litter of kittens recently, and they all act very well. They're almost ready to be weaned, and we don't want her teaching them to beg, or steal food, or bite, plus we need to cut down how many cats we have in a safe and responsible manner. We've decided to keep three (so far) plus my fat, lazy Siamese, which is about the saturation point for cats. We have a home for one waiting for when they're weaned, but that leaves us one kitten (who acts wayyyy too much like the mother) and the mother, who is steadily getting worse in her behavior. We want to find a good no-kill solution, but it's hard unless anyone knows of an animal sanctuary closer than the Caboodle Ranch...
How about taking her over to a farm? They always have rodent problems, and she'll be able to live outside where the feral behaviour can be productive.
I'm with Krikkit, farm it off to someone else... You can't teach an adult cat anything; we're currently going through the rubbing it's nose in it routine, it works for a few days, even weeks, then she's off again; pushes her mother off their bed; ignores the water inside, drinks from puddles outside, throws up inside; sneaks upstairs to poo where the rabbit sleeps (don't ask) if you accidently leave the door closed, but not clicked on the latch; and generally makes a nuance of herself... and it's not even my cat!
Make sure you get any pet cats or dogs you own neutered, unless you want them to reproduce in an uncontrolled manner & then have to sort out neutering & vaccinating the offspring... repeatedly.
+1 to farm. My quite old grandpa has a farm in Washington state and loves every last cat he has. I can think of no better opportunity for a cat, especially a feral one.
I would have to agree with farm idea also. We currently have 4 cats as well, 2 kittens and 2 adults. One of the adults was a feral, she was about 15 weeks old when she came to us. She can be very possessive and bad tempered but on the whole quite sweet. She has attacked both me and my partner when she was a lot younger but that would only happen if you talked to her when she was sitting on you! She still doesn't like being talked to now but doesn't react with claws and teeth anymore. We do have a referee of sorts for the cats which is our old english sheepdog, who loves pretty anything and everyone. He generally tends to split the cats up if they get a bit feisty with each other. Is the cat allowed outside at all? Does she have a cat flap to come and go? If the cat is now being kept indoors most of the time, then the behaviour would be quite understandable as she might never have been house trained and she probably doesn't see the difference between inside and outside in the way she should act.
I wouldn't agree to sending the cat to an unknown farm, I live on a farm at home and there nothing but pests if they get out of hand. We have around 6 cats all neutered that we feed and look after, Any extra are got rid of because they become inbreed + other problems. Its sad to admit that but it costs so much including vets fees etc + the cat protection refuses to take them. Luckily my mini cat mafia keeps them at bay
...harsch but...keep her away from the kittens if this starts to rub off, or you'll never get rid of those either. My cat's a bit of an attacker, never learned that "Play" means "keep the claws in". And he loves to play. At least he's clean
We live next to a highway, a deaf cat outdoors is a flat cat. We do know people with barns, who use barn cats, so we'll see if we can't find one of them to take her.
Contact an American equivalent of Cats Protection, the largest UK cat charity, and ask their advice in your specific case. They'll be more than happy to advise you of what action is in the best interests of the cat. That's what they do after all.