Computer mouse. Artwork based on an X-ray of a computer mouse being held and operated by a human hand. A 'mouse' is a computer peripheral device. Its attachment lead to a computer is seen at top. A set of control buttons are operated by the index and third fingers of the hand. The mouse contains a small rubber ball that spins as the mouse slides over a flat surface. Electronic sensors detect the ball's movements and translate them into corresponding movements of a pointer or other icon on a computer screen. The mouse allows people to use computer programs without having to type complex codes on a keyboard.