Re: How do I keep feral cats away?
Welcome to CatForum and I hope we can help. First, we need more information before we can think of ways to help. I truly do not think it is fair to make the cats suffer by making the food they expect to eat taste nasty when they have been conditioned to find food at this location. You would not like to be served food you've known in the past to smell/taste good and have it presented before you and be unpalatable. I don't think it would be fair to do this to cats who are annoying you through no fault of their own and I come to The Big Question:
Exactly how are these cats ruining your life?
Please pardon me for saying so, but reading-between-the-lines, is this because the person feeding them is devoting themselves to these cats and not the people under her care? If this is the issue, this isn't a problem from the cats' end ... it is a mental issue for that person feeding them while ignoring her familial responsibilities and obligations ... and unless/until that is addressed and remedied, you will experience problems with that person and their particular problem right now is devoting themselves in an unhealthy manner to the cats.
If the problem is one of the cats hanging around and making nuisances of themselves, perhaps the feeding station can be moved further from the home.
One last thing, if these cats are spayed/neutered then I feel they can't be feral.
Are they neighborhood kitties coming for the free buffet and have homes of their own?
Are they abandoned housepets who don't have hunting skills to be able to survive on their own and need this food, having reverted out of self-preservation to feral tendencies?
It sounds like a difficult situation and I hope we can help you find solutions.