Mickey

One mickey is the smallest resolvable unit of distance by a given computer mousepointing device. It is named after Walt Disney's Mickey Mousecartoon character. Mouse motion is reported in horizontal and vertical mickeys. Device sensitivity is usually specified in mickeys per inch. Typical resolution is 500 mickeys per inch (16 mickeys per mm), but resolutions up to 16,000 mickeys per inch (600 mickeys per mm) are available.

Huh now that's interesting. Like roughly the size of an exit button on a mobile ad