What's adorable, efficient, and actually hums while tidying your house? When you're away, robotic vacuums will play, and even clean your carpets. Consumer Reports put three of the latest models to the test to see if they truly do as they claim - effectively clean your floors. This night-vision camera shows how they work. Their infrared sensors help to get them out of tight spaces, find dirt, and even keep from falling down the stairs. They stop cleaning when their bin is full and return to their docking stations when they're finished. But how well do they clean? Consumer Reports' testers pitted the three robots against measured patches of cereal, sand, rice, cat fur, and paper bits. "Check out this time-lapse photo. The Roomba did better simply because it covered all areas of the room several times." Other models are more systematic, moving in straight lines across the room. They pass over the area once, so whatever litter they miss stays there. Consumer Reports recommends the iRobot Roomba, at about 450 dollars. It did an excellent job in all of Consumer Reports' tests. John McAloon "It took a little bit longer to do the room than others, but if you're not there doing the work, what does it matter?" Robotic vacuums are easy to program to tidy up your home while you're away. But they can't replace your regular vacuum for deep-cleaning carpets. "