Fig. 2.—Cicada, as in life.
Fig. 3.—Cicada, showing "drums" (marked D), magnified.
But many insects, like the crickets and grasshoppers, have a specially constructed instrument on which they play. Fig. [1] shows a part of the instrument used by an American grasshopper. It is formed by a row of tiny teeth, marked t, placed along the inner side of the thigh of the great leaping leg. When this creature feels very happy, or wants to charm his mate, he produces a shrill sound by rubbing these teeth across the hard 'nervures,' or wing 'veins.' What these teeth are really like can be seen in the lower part of the illustration, which shows eight little spear-heads set in sockets. These are 'teeth,' which act much as a comb would do if drawn lightly over a tightly stretched wire.
Fig. 4.—Scorpion, in act of "playing."
The 'stridulation,' as this form of musical production is called, in some locusts is so loud that it can be heard on a still night for a distance of a mile. Some South American locusts are such wonderful performers that the Indians keep them in wicker cages, in order that they may enjoy the playing. There is a North American locust which is quite famous as a musician. It is known as the Katydid, on account of its peculiar notes, which resemble the words Katy-did-she-did. This note is kept up throughout the night. Our field-cricket plays by rubbing a row of teeth, about one hundred and thirty in number, placed on the under side of one of the supporting rods, or 'veins,' of the wings, against another rod very like it, but without teeth, in the upper surface of the opposite wing. First one wing is rubbed over the other, and then the process is reversed.