New research show wallabies are low "emitters" of methane - unlike cows - and instead produce another chemical during digestion. Filmed at Cleland Wildlife Park, Adelaide, during our recent trip to Australia. More chemistry at http://www.periodicvideos.com/ Follow us on Facebook at http://www.facebook.com/periodicvideos And on Twitter at http://twitter.com/periodicvideos Periodic Videos films are by video journalist Brady Haran