Excessive litter box scratching

My momma cat has this thing about scratching, scratching, scratching (did I mention scratching) around in the litter box FOREVER after she goes. She is using it, so I am not sure what this is about. I'm worried about trying to change this for fear that she might take it to mean I do not want her to use the litter box.
Does anyone have a kitty that does this? Why and can you change the behavior?

Ping has always been one that scratches and scratches in his litter box. But he does not scratch the actual litter. He scratches the sides and top of the box. I have yet to find a way to stop it. I just let him scratch until he bores with it.

Gracie and Elliott do the same thing.
Gracie of course scrathes the litter before she goes, after to cover it up but then she goes for the sides and the top of the box.
Elliott does the same thing, but he never covers anything, so Gracie goes in after him and covers for him, she does the same with Annabelle ( she doesn't always cover either )

Marco digs like he is trying to reach the other side of the world. I had the not so brilliant idea of talking to him when the excavating began to distract him [he's a bit intense about his digging]. He decided to show me his digging works just as well on my plants. At that point I got a clue and just left him alone..

UGH... I WISH Horatio WOULD scratch in the litterbox... he just poops and leaves... BLEGH... then if I smell something, I know he's gone and I cover it (to get the litter all on it) then I scoop it out right away.

He has horrible litterbox manners.

Haha I think Oliver tries to dig to China when he's in there... he scratches a bit before - I guess to clear a spot - then sticks his head out the door (he's got a covered box with the door taken off) and makes his poo face, then digs digs digs digs digs digs.... in the litter on the sides on the lid... then, whoosh! He shoots out of the box and tears around the house... it only bothers me at 5am when I'm trying to sleep and he wont stop digging and then begs to get out of the room in order to run around - what a little monster

Haha...my kitten does the same thing. Ike is about 3 months old, she (yes 'she') walks around the box to find a good place, does her business, then scratches all around, she moves almost all the litter around, just NOT covering her mess...then after about 5 mintues, she gets it covered, then proceeds to scratch the sides, tops of the litter box and EVEN the sides of my table that it is under...pretty much everything w/i 5 feet of it.

It has never really bothered me, I just think its funny.

I clicked on this thread hoping someone had found a solution to that, because Mellie does it too, and I've never found a way to stop it. I guess I'm still looking.