1 The mouse can work only on a clean, flat, and non-slippery surface in order to ensure smooth and accurate cursor action. 2 This optical mouse senses light to detect mouse’s movement. When it works on the glass, translucent, reflective, or dark-colored surface, the mouse movement may be affected sometimes. 1 2 3 4 We recommend using alkaline batteries for a longer battery life. Don't mix different types of batteries or new and old batteries together.