Have you ever noticed your cat pawing at the floor around her food dish? Have you ever wondered why she does that? Perhaps you've also noticed the occasional toy or other piece of "prey" in her bowls. It's behavior that speaks to cats' wild heritage; these behaviors mean she's staking out her home.
Cats see their food and water bowls as part of their lair. They might see the whole area around their bowls as their lair. In the wild, this might be inside a tree, or in a small alcove or cave formed by rocks. At home, though, she might have two or three lairs, and her bowls are in one of them, even if they're out in the open.
When she's pawing around her food bowl, she's "burying" her leftover food so that another animal doesn't smell it and steal it, or try to fight her for it. Watch her while she does it. She'll paw a few times, then sniff at her food, and then paw some more and sniff some more, until she's either satisfied, or convinced she can't cover her food well enough. The same is true of her litter box behavior. Leaving her food (or her waste) out in the open might as well be an engraved invitation for predators to come into her lair.
If she's painting around the inside of the litter box, there's a chance that she's doing it because she's unhappy with the condition of the box. Cats often prefer bigger boxes with litter that's at least 3 inches deep. That gives her sufficient room to bury her wastes. She might also be trying to send a message about how clean the box is (or isn't), especially if she's not the only cat in your house.
This behavior is nothing to worry about. In fact, it's a good sign that your house belongs to your kitty.