Cats are known to scratch their litter after using the restroom. But have you ever noticed that they may scratch outside/within the litter box or around their food bowl?
Scratching after using the litter box -
Cats may scratch outside and around their litter box as a way to claim their territory. Cat paws have scent glands and they are NOT, and I repeat, not afraid to use them;
If it's a multi-cat home this may be a way of them communicating to their fur-siblings that their scent is on that box - this communication is often followed by cats who scratch the wall around the sides of the litterbox;
In the wild, felines are known to bury their waste to avoid being detected by predators - so it may be chalked up to their ancestral ties;
Your cat may be trying to communicate to you a) that they do not like their litter, b) that they need more litter in the box and/or c) that the box needs to be cleaned (all followed by excessive scratching within the box).
Scratching around their food bowls -
Cats may scratch around their bowls to 'hide' their food. Your cat is in essence burying their leftovers so they can come back to it when they're hungry;
As a way to hide the scent of their food and instead release scent glands from their paws to claim the food and that space;
This can also be done as a way to keep their space clean. I personally have a cat who is obsessively clean, to the point of me seeing him go to the extent of him 'cleaning' up his brothers food crumbs.
Note: some cats may excessively scratch unacceptable areas in the home. If you're unsure why I recommend reaching out to your veterinarian.