Although you may not hear it, rodents have been known to talk to each other with high-pitched sounds that are impossible for human ears to pick up. Now, scientists have discovered that these calls may have another purpose - helping them smell better.
For decades, scientists have been recording the sounds rodents make at ultrasonic frequencies, which are said to be a form of communication that may help them find mates. It might even be a form of laughter, because according to one of the cutest studies in recent years, they also do it when researchers tickle them.
In a new study, University at Buffalo scientists have discovered another potential, unexpected benefit of ultrasonic pulses in rodents. The animals can use these sounds to stir up particles in the surrounding air, which they can quickly inhale, enhancing their already strong sense of smell.
Eduardo Mercado III, a co-author of the study, said: "This phenomenon has never been observed in any animal before, and I believe there is no even doubt. They are creating new information pathways by manipulating the surrounding environment and controlling the molecular interactions of the surrounding particles."
The researchers were initially inspired to investigate the idea by previous studies of how rodents navigate their environment. Research has found that rodents typically sniff the air immediately after each ultrasonic vocalization (USV).
"This could be a coincidence, or it could indicate that the two are functionally related," Mercado said. "I knew about the field of vibroacoustics, which uses ultrasound to manipulate particles, and immediately thought that this might also apply to animals."
Vibroacoustics is a field of study that uses ultrasonic vibrations to create clumps of particles in the air. The team speculates that mice and rats may be doing the same thing, creating clumps of odor molecules that are more easily picked up by their sensitive noses. This may include pheromones left behind by friends, rivals, and potential mates.
Although researchers have proposed this concept, it has not yet been experimentally confirmed. But it's an intriguing idea that could reveal new insights into animal behavior and abilities that might be hiding right under our noses.
The research was published in the journal Neuroscience & Biobehavioral Reviews.