From an early point in your life, you probably learned about the dangers of electricity. You know not to put your fingers into electrical outlets. You know not to use electrical appliances near water. You know not to climb electric poles.
So it may have puzzled you the first time you saw birds and other small animals, such as squirrels, running along and even sitting for long periods of time on electrical wires high up in the air. At times, electrical wires can be filled with dozens and even hundreds of birds.
Are they getting shocked while they sit there? They must not be, right? After all, you don’t hear any screeches or see puffs of smoke and feathers. There’s no smell of roasted bird in the air. So what’s the deal? How can birds sit on electrical wires and not get shocked?
Their cells and tissues do not offer electrons an easier route than the copper wire they’re already traveling along. As a result, electricity passes the birds and keeps flowing along the wire instead.
Another reason why electricity will bypass a bird sitting on a wire is that there’s no voltage difference in a single wire. For electrons to move, there must be what scientists call a difference in electrical potential.
For example, electricity flows from areas of high voltage to areas of low voltage. Electricity flowing through a single power line at 35,000 volts will continue along the path of least resistance and bypass birds because there’s no difference in electrical potential.
When does it get shocked?
If the bird would touch the ground while sitting on the wire or flap its wings and touch another electric wire with a different voltage, then it would get shocked and likely die from electrocution.
This is because its body would become a path for the electricity to reach either the ground (no voltage) or a place with a different voltage (another wire at a different voltage, for example). This is why power lines tend to be high in the air with plenty of space between the wires!