Cat just sitting hanging out with my other cats

I couldn't believe it yesterday on my deck all my cats were laying down so relaxed and i saw another cat at first I thought it was my own but then realized it wasn't! I leave food for my cats outside sometimes and she eats from their dish! What i dont get is my cats were so at ease and so calm around this strange cat? no hissing no NOTHING, everyone was in a good mood until the cat saw me and DARted off.

Could this cat be wild? she looks so healthy and nice! But she wont let me near her at all! She came back twice right away as soon as i left to eat the rest of the food but soon as i went outside boom she ran away! How do i know if she is just shy or actually wild? She is very healthy looking cat so if she is wild she must have a great food source?

Whether the other cat is owned or feral, it's pretty normal for indoor/outdoor cats to make friends on the outside world. After they've been sharing a neighborhood for a while, they get to know each other, and establish a hierarchy. Just be glad they're not fighting instead.

It's not all that surprising. I've seen it happen often. Not with my own beasts (my alpha lives for a good fight) but I've seen it with cats I pet sit.

But if they were INdoors, they would fight over territory... I also came home one night to find what I thought was my cat coming in the window (dead ringer!), until I turned and found my 'real' cat coming from the bedroom, but I wonder if they weren't related because mine hadn't yet been fixed. Another one moved in over about a week or so, and we really thought we'd keep him, but after a while it was just too many (we had others too) and we found a great new home for him. But that was many many years ago and we haven't let our guys out alone in a very long time.