http://www.nytimes.com/2006/12/26/science/26bubble.html

Dr. Catania made his original observations with the naked eye, but in recent years has been recording star-nosed moles with high-speed video. Using this technology, he noticed that the star-nosed moles were actually producing up to a dozen bubbles each second, but most of the bubbles never detached from their noses. Instead, the animals sucked the bubbles back in.
The bubbles resembled the puffs of air the moles used to smell objects out of water, Dr. Catania noticed. He also observed that the animals released their bubbles only when they were investigating objects.
“The bubble comes out of the nostril and spreads over the thing they’re exploring, and then gets sucked back into their nose,” Dr. Catania said. “So it’s essentially an underwater sniff.”
