This is very typical of the domestic cat. Being serious for a minute, this is not about the cat preventing his human guardian from using their computer mouse. It’s about playtime bordering on hunting (and therefore a little bit too aggressive).
This blue British Shorthair (a popular cat breed and coat colour) thinks that his human friend and caretaker is playing. It is a fun game. As soon as the person puts their hand on the mouse the response is to grab or nip it. These sorts of play moments occur spontaneously because cats like to play as an expression of hunting.
In this instance the cat has become a little bit too feisty for nice play. Cat play can quite easily degenerate into aggression because it is based on aggression in all honesty. It is based on hunting. This is how many people are scratched or bitten when playing with their cat. It is up to cat guardians to manage play sessions to make sure it goes well for both parties 🙂 . This means not winding up the cat to the point where she goes for the killing bite on your hand.