A Mouse is a common computer peripheral apart from the keyboard. Even the touchpad is not able to dent the popularity of mouse. Nowadays the keyboards, as well as mouse connect through the computers via USB cable or the fancier one connect to the PCs wirelessly through Bluetooth. This project is an attempt to demonstrate the functioning of a generic USB mouse. The 8-bit USB AVR - Atmega 32u4 is used as the USB device controller in the project. In order to avoid complexity, the project uses AVR based Lightweight USB Framework (LUFA) as the firmware.