Taking cues from the firefly, a Dutch electronics company has created a product called “Bio-light”—an eco-friendly lighting system that uses glowing, bioluminescent bacteria. They’re not powered by electricity or sunlight, but by methane generated by the company’s Microbial Home bio-digester that processes anything from vegetable scraps to human waste. The living bacteria are fed through silicon tubes, and as long as they’re nutritionally-fulfilled, they can indefinitely generate a soft, heat-free green glow using the enzyme luciferase and its substrate, luciferin. They’re kept in hand-blown glass bulbs clustered together into lamps, but you can’t light up your house with them yet—the glow isn’t nearly bright enough to replace conventional artificial lights. They do, however, get people to think about untapped household energy sources and how to make use of them. The company, Phillips, also envisions the use of these Bio-lights outside the home—for nighttime road markings, signs in theatres and clubs, and even biosensors for monitoring diabetes.