Baron Jakob Johann von Uexkull, a Baltic German biologist, mentioned in his book entitled Stroll through the World of Animals that all creatures, including plants, on this planet live in an Umwelt (German, literally “environment”) ~ that is its own sensory world evolved to satisfy its particular requirements. A dog, a bat, a bee, a tick, a human etc. all live in the same physical world, but each perceives and interacts with it in vastly different ways. The 18th-century Italian naturalist Lazzaro Spallanzani was puzzled, for instance, by the way bats could fly in the dark, but it was not until 1938 that Donald Graffin, the American zoologist, discovered they were able to find their way by using high-frequency sounds.

The invention of the ultrasonic microphone, together with the invention o

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