We used to have some ferals when I was young as we had stables and outbuildings etc and the local RSPCA used to place feral cats with us. We ended up with quite a few, they were always a bit mad. You can domesticate the kittens but the adults are quite wild. People still rehome them though, friends of ours have a couple as they have land and buildings so the cats can come and go as if they are 'wild'.
Is there any way to catch them, they can spread feline leukemia and cat flu as they won't have had their jabs, so it might be worth seeing if they look really healthy as if not the charities might come and take them on those grounds.
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