<http://schema.org/about>
"The sight of a prowling kitty isn't the only thing that sends a mouse's defense mechanisms spinning into overdrive\u2014the presence of carbon dioxide also signals danger, whether it's because too many animals are breathing in"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/natural-sciences/mice-can-sniff-out-co2-in-the-air.html>