This should answer all your questions:
They bring you dead animals... this isn't a gift it's a warning.
They engage you in staring contests... don't look away it signifies weakness.
Kneading your stomach.... Checking the placement of your internal organs.
excessive kitty litter digging....They are practicing to bury the body.
You find a knife in the litter box.
They creep up on you, jump on your shoulders, and scratch you like no tomorrow. Ninja kitties.
Poop in the flower bin.
They sit on your face while you're sleeping.
you'll never know...