The antenna are used for "vibratory wave selection within the insect's environment"..."The radiesthesic faculty in man appears to be the same used by homing pigeons, dogs, and even moths..." "The antenna of the moth and butterfly makes them expert diviners of vibrational patterns..." These are quotes from Christopher Hills.
You are going to have to prove this one to yourself. Get out a volt meter and see if you can detect polarity in your own two hands, left vs. right. If you have sensitive enough equipment you can find that each finger has an alternating polarity, the index finger is opposite the middle finger, etc. What fingers you use to hold a pendulum or rod makes a difference.
Every cell in the human body is a wet cell battery.