The moles reached their reward—an earthworm—about 85 percent of the time.
"Discovering a very unusual behavior in an unusual animal raises the question of whether or not some other animals are capable of it," Catania said.
So zoologist Kevin Campbell at the University of Manitoba in Canada provided Catania with water shrews that also blow bubbles while foraging underwater.
Reporting in tomorrow's issue of the journal Nature, Cataina found that during a similar experiment one shrew was accurate in following 80 percent of the trails, while another had 85 percent accuracy.
"In a lot of ways it's more compelling to find a normal-looking animal doing this behavior," Catania said. "It might be a common thing for small mammals to do."
Neal Woodman studies shrews and other North and South American mammals with the U.S. Geological Survey Patuxent Wildlife Research Center's office at the Smithsonian Institution in Washington, D.C.
He said the finding makes sense; the small mammals probably use both smell and touch when foraging underwater.
(Related photo: marine iguana foraging underwater.)
Previous researchers must have ignored—or just didn't see—the bubble-blowing behavior.
"What this [study] does is say, Hey look, the sense of smell really is possible here. We should look at it more carefully and consider it. It's an important study," he said.
In future research, Vanderbilt University's Catania hopes to determine how common underwater sniffing really is.
He believes that other small, semiaquatic mammals probably evolved the ability.
But he suspects that air bubbles blown by larger mammals may not hold together well enough to survive the exhale-inhale sniffing action.
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