The Harvard katydid.
The physicist, Professor George
W. Pierce, of the Cruft Laboratory at Harvard University, has studied
the songs of insects.
There was a katydid in Dr. Pierce's laboratory that learned to count and thereby alter its
usual two-beat rhythm. During an experiment, a laboratory assistant who could imitate the
katydid's shrill "zeep-zeep," made the sound in three beats instead of two. The
katydid answered with three beats. The assistant then tried four, and the katydid answered
with four. Then the assistant tried five and the katydid answered with five. At the next
stage, however, the insect lost count and, on its own, began to improvise on the numbers
it had already learned.