I was thinking about entering the bank when a tiny roomba with a dead battery crashed on the pavement in front of me, leaving a crater of rubble and plastic.
Tiny Roomba, like the robot in OA, won't require power to stay stuck to window.
Tiny Roomba, like Roomba's today, will know it's power reserves and be able to return to charging station before shutdown.
Tiny Roomba will be solar powered.