connecting a mouse to a mega2560

I can only find endless topics where the arduino emulates a mouse.. thats not what i want..I simply want to plug in a usb mouse and be able to use it as an input device.. is there a standard mouse_input lib or somesuch ...i hope..
thanks for any helpp--

You probably are going to want a “USB host shield” and the appropriate library for that shield. You could also connect an old PS2 mouse to the Arduino without needing a shield.