The cause of a mouse cursor moving by itself may be one of several options, depending on what type of trackpad or mouse a user has. Water, dirt and electrical interference are the most common causes of a trackpad malfunction.
Jumpy mouse cursors are caused by mechanical or software-based issues, and the cause of an erratic cursor may be different depending on the hardware being used. Trackpads work through a process called coupling capacitance, whereby two layers of electrodes in the trackpad monitor the change in capacitance as a finger or stylus moves across its surface. For the trackpad to function properly, it needs complete contact with the fingers controlling it. To fix an erratic trackpad, users should clean the trackpad and their hands to remove any grime, skin oils or lotions. If that does not work, users should disabling the "tap to click" option on their laptop and check the laptop battery for signs of swelling, which can press the battery into the trackpad and cause malfunctions. Mouse malfunctions can be caused by similar issues but can also sometimes be solved by updating the mouse drivers on the computer. Users should check for new software, uninstall the old drivers and reinstall the new ones. If the problem is caused by the mouse's sensitivity, a user should find the mouse's settings and reduce the hardware acceleration. This reduces the pointer's acceleration as it is moved.