The non-flushing or the bio-digester toilet developed by the Defence Research and Development Organisation (DRDO) for the troops serving in Himalayas is now being offered to private companies and poor Indian states. The toilet conceived by DRDO unit at Gwalior works by mixing self-multiplying bacteria with human waste in specially-made tanks, resulting in the production of methane gas and water. Lakshadweep Island has already sought 12,000 bio-digesters for a major housing project.