How to Clean Your Mouse: An Illustrated Guide

One of the most common desktop support issues I have encountered as a nonprofit consultant is a misbehaving mouse. I've watched people struggle for untold minutes with a troublesome mouse in order to perform the simplest functions. While a software bug, a virus, a broken mouse, or a frayed mouse cable can produce similar effects, most often the problem is the result of a dirty mouse.

Many mice, especially older ones, contain a small rubber ball held in place by a set of rollers that detect the ball's motion as the mouse moves back and forth across a desk. Over time, this ball picks up dust, oil, food debris, and other crud that accumulates on the rollers, interfering with their ability to register the ball's movement, and causing balky, jumpy, stilted, or erratic cursor movements onscreen.

So before you search your system for viruses or crawl under your desk to inspect the cables, try following these simple steps to clean your mouse -- an operation that requires little more than a fingernail. (The tip of a small flathead screwdriver or a wooden manicure stick will also work.)

First, to get at the rollers, open the bottom of the mouse by turning the collar on the bottom clockwise to disengage the tabs that hold it to the body. The mouse pictured here is made by Logitech, but most mechanical mice have a similar anatomy.

Once you have opened the mouse, turn it over. The collar and roller ball should fall out of the cavity.

With the collar and ball removed, you can see the rollers inside of the cavity. Most mice have three rollers -- two for sensing the ball's motion, and one mounted on a spring that pushes the ball into the other two sensors. On the mouse pictured, the tension roller is white (figure 3) and the sensor rollers are black (figure 4).

It's easy to see the line of accumulated dirt -- and the source of the mouse's tracking problems -- stuck to the tension roller. To remove these deposits, use your fingernail, screwdriver, or manicure stick to scrape the roller in a side-to-side motion. With the tension rollers, it's often necessary to push the roller in a bit and then scrape.

Once you've removed the crud from the rollers, place the mouse on your desk and tap it to knock the remaining dirt out of the rollers and guts. It is sometimes helpful to blow into the cavity to fully release the debris lodged deeper inside.

Here is a picture of the tension roller after cleaning.

To reassemble your mouse, place the roller ball back in the cavity and twist the collar back on. Your mouse should now function smoothly and easily. Perform this cleaning ritual once every month or two to ensure a healthy, happy mouse.