 According to the Jain leader Mahavira, the humans destroy these nigodas on a massive scale, when they eat, breathe, sit and move.Many modern Jains assert that Mahavira's teachings presage the existence of microorganisms as discovered by modern science.The earliest known idea to indicate the possibility of diseases spreading by yet unseen organisms was that of the Roman scholar Marcus Terentius Varro in a 1st-century BC book titled "On Agriculture" in which he called the unseen creatures animalcules, and warns against locating a homestead near a swamp