Near the corners of the maze are four larger, flashing dots known as Power Pellets that provide Pac-Man with the temporary ability to eat the ghosts and earn bonus points. The enemies turn deep blue, reverse direction and usually move more slowly. When an enemy is eaten, its eyes remain and return to the center box where the ghost is regenerated in its normal color. Blue enemies flash white to signal that they are about to become dangerous again and the length of time for which the enemies remain vulnerable varies from one stage to the next, generally becoming shorter as the game progresses. In later stages, the enemies go straight to flashing, bypassing blue, which means that they can only be eaten for a short amount of time, although they still reverse direction when a Power Pellet is eaten; starting at stage nineteen, the ghosts do not become edible (i. e. , they do not change color and still make Pac-Man lose a life on contact), but they still reverse direction. There are also fruits, located directly below the center box, that appear twice per level; eating one of them results in bonus points (100–5,000).