Strange thing this cat does

So I got a foster cat today that's hugely pregnant. (I felt the kittens moving which was cool).

But this cat is doing something I've never seen before.

You know how a cat will knead when he/she is purring? This cat does that ALL the time??? I mean it's strange. But she also has this weird thing. She'll pick up one leg and curl it up. Then let it out, set it down and do the same with the other. It looks like something she'd do if she were standing on really hot or cold ground.

Anyone ever seen that?

Sometimes my cats do it when they accidentally step on tiny ants.

Ana does that while she's kneading, it's very cute

One of my girls LeLe does that when I'm talking to her and she's listening. The stray cat that I think is her Father does it (who has been spayed). Its some kind of contentment thing I think

Baby does that while her kittens are nursing, she also croons softly to them, it's so adorable.