Mouse flap

My cats have the nasty habbit to bring live mice inside the house and let them go (to hunt them later I suppose). Anyway my cat flap cam registered their latest victim trying to get out and I felt a bit sorry for the little animal.

According to the numerous fotos my cam sent, the mouse kept around the cat flap, maybe trying to get out the way it came in? It gave me the idea to install a mouse escape hatch (or less dramatic; a mouse flap).

It only has to be a simple flap, just a one-way opening to provide an exit for the trapped prey. Spent a little time with OpenSCAD (http://www.openscad.org) to design this.