Agriculture, you see, is a gassy business. The 1.3 billion large ruminants—dairy cows and beef cattle, buffalo, sheep, goats—that burp, fart, and poop around the world emit more greenhouse gases than does the transportation industry, according to the UN. (See an interactive on the greenhouse effect and global warming.)

These animals are responsible for about a third of global emissions of methane, a gas that makes up half of farming's contribution and is even more potent than the much-maligned CO2. (The other big methane offenders: the natural gas/petroleum industries and landfills.)

So any animal helping to quell gas release invites investigation. In a paper published August 7 in the journal PLOS ONE, Atte Penttilä and colleagues from the