The San Antonio-based manufacturer of a virus-killing robot says its services are much in demand lately. The robots from Xenex Disinfection Solutions are being used in healthcare facilities nationwide but are also doing duty in commercial and residential spaces. CEO Morris Miller says the robots kill germs and viruses with powerful ultraviolet lights in high-intensity Xenon lamps. He says they're being used in restaurants, day cares, gyms, office buildings and homes. Miller says some businesses call when an employee tests positive, but others have the robots come by on a weekly basis.