A computer mouse includes a housing, a first container secured in the housing, and a second container secured in the first container, a timing unit, and a processor. The first container defines through holes. The first container and the second container are spaced by a distance to define a receiving space being partly filling in liquid. Suspending members extends through the through holes. One end of the suspending member is received in the receiving space. The density of the suspending members is less than that of the liquid Sensitive switches are attached to the first container. A method for the mouse includes determining whether any one of the second contacts is charged; generating a position signal, controlling the timing unit to time; determining the movement direction of the a cursor; determining the movement distance of the cursor; and generating cursor control signal for controlling movement of the cursor.