There are robot vacuums that can either operate in complete darkness or have infrared emitting bulbs that can detect objects at night. This is a more comfortable way for the robot vacuum to clean around the house late at night when you would prefer to be asleep. If your current robot vacuum cannot operate in complete darkness, you should look into getting one with infrared sensors. This type of vacuum cleaner actually works very well in dimly-lit settings, including under beds and couch cushions.