circuit is intended to drive-off the female mosquitoes with a super
sonic sounder. Most of the time when a mosquito is pregnant, she
needs more valuable food and will look for humans or other sources
of nutrition. In the meantime, she dislikes keeping in close with
the male mosquitoes and prefers to look for food alone. Thus, this
circuit is intended to produce a sonic frequency range that drives-off
the female mosquito.
The two transistors link as a multi-vibrator oscillator circuit
while R1, R3, and C2 control the super sonic frequency. The piezo
element is the sounder.