So I was surfing for a reason or similar thing that my cat does, and this is the closest I came. I know what it is when they are kicking litter or fleas or something they stepped in off their feet. This just isn't the same thing. My cat Rebe is the only one of six that does this strange thumping. I call it wall thumping because she literally backs up to a wall or door or cupboard door and thumps her back foot as fast as she can against it. I'm really glad she isn't the only one doing it. I was thinking she does it to ward off other cats or maybe she hears or smells something and is warning whatever it is that this is her domain. These are the best explanations I can come up with. If I can catch it on video I will post it. She is also the kind of cat that gets into everything and anything especially when she knows she's not supposed to.
Haha. She is very intelligent and even pulls her own pull string toys to make them go. I do have that one on video. She dumps the toy basket just to find the one she wants to play with. So I think it's some form of communication (wall thumping) that she's doing, I just haven't figured out what she's saying yet.
Cat lover forever!