Cats... then and now

Way back last summer a cat family consisting of a mother and two daughters was abandoned when neighbors moved away.  I reluctantly started feeding them in my barn, partly because I felt sorry for them, but also because mice and rats had been showing up more often than I like.  
Now, I've had trouble in the past with cats climbing on the window screens and causing some damage, so I hoped the cat family would stay away from the house.  I have never once petted any of these cats, and if they get too close I give them the boot.  Not real hard, mind you, but enough to discourage them away from under my feet.  This has served to make them very wise, so they can now estimate exactly how close they can get to me without getting kicked.  You'd love it if you could see me vainly swinging a toe at any of the three.  I miss, every time.  They laugh.  
I did not intend at any time for the cats to come near the house.  I only feed them in the barn.  And yet, when I open the front door, I often see a couple of cats scurrying off the porch from their comfortable perch on our porch chair.  They aren't stupid; even though I don't feed them at the house, they know I live in the house, and they hope to persuade me to feed them a little extra.  
They have yet to climb on a screen, so I guess they got the memo I sent them about that.
Lest you think I'm a terrible cat mom, I'd like to show you a picture of them when they first moved to our place:  

Mom is on the right.  All three were scrawny, and that calico was downright sickly.  

Here they are this morning in the barn, eating their generic Walmart cat food.  Cliff says they are "slick as moles".