What’s that clicking sound?
That’s the sound of energy being discharged along the fence wire.
The flow of electricity is regulated by an energizer (also called a charger). It stores electrons in a “capacitor” and then releases them in a “pulse”; after each pulse the capacitor stores up electrons for the next pulse.
Clicking indicates pulses being released by the second. However, each pulse lasts a tiny fraction of a second.
This is meant to allow a bear to get away from the fence once it has taken a shock i.e the connection will last but for a split second so the bear won’t be “stuck” to the fence. The bear will be deterred, shaken, not harmed.
If you hear something else or in addition, like a popping, fizzing or crackling noise, there might be something wrong: go check your set up for a short (see the FAQ “How do I know if the fence is working properly?”)