Paramecia (image) Brown University Caption Cilia -- short, hair-like fibers -- are widely present in nature. Single-celled paramecia use one set of cilia for locomotion and another set to sweep nutrients into their oral grooves. Researchers at Brown have discovered that those two cilia sets operate at different speeds when the viscosity of the environment changes. That suggests different molecular motors driving them, which could help explain how cilia have come to be used for so many different tasks in nature. Credit Valles Lab / Brown University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.