A mechanized iris is built into the top of a coffee table. This is attached to an infra red motion sensor. Crumbs and food debris left on the table attract mice who gain access to the tabletop via a hole built into one over size leg. Their motion activates the iris and the mouse falls into the microbial fuel cell housed under the table. This generates the energy to power the iris motor, sensor and a LED graphic display on the front of the table–top.