Grasshoppers, crickets and locusts all have knee-ears that, at just a fraction of a millimetre long, are among the tiniest ears in the animal kingdom. Even though countless numbers of these insects had been dissected, no one had really understood the structures of these ears.
Like most animals, a grasshopper hears by receiving and processing sound waves. When the sound waves are received by the grasshopper, they act both on the external tympanum and the internal chambers. The interaction between these two pressures and the tympanal membrane results in the grasshopper’s ability to hear. This mechanism is so sophisticated, that a grasshopper’s ability to identify the direction of a sound source rivals that of a human.
Aside from locating and avoiding predators, acoustic communication in grasshoppers is mainly used for the attraction of mates. The male initiates a call, often a whirring or snapping noise, which is heard by the female. The male then listens for her response, and due to his sensitive hearing, is able to pinpoint her location with relative ease. Thus, a grasshopper’s ability to hear helps ensure the survival of the species.
Credit : National Geographic
Picture Credit : Google
