Ever heard the saying that "dogs can smell your fear"? The saying turned out to be true: Julien Brechbühl at the University of Lausanna, Switzerland, and colleagues showed that mammals can communicate dangers to each other through smell.
Scientists at the University of Lausanne, in Switzerland, found that when mice are placed in an environment where there is a beaker of water containing alarm pheromones emitted by other mice, they immediately sniff out the danger and move away from the beaker.
The mice's keen reaction has been attributed to the 300 to 500 cells found at the entrance of their noses, called the Grueneberg ganglion. This ganglion is present also in human beings, according to the scientist Hans Grueneberg who discovered it in 1973.
The Swiss authors of the new study, led by Julien Brechbühl, speculate that "one can imagine that humans have a similar method" of communicating danger to each other.