A bird perched on a single high voltage wire is unharmed because:

1. Current flows through a body only when a potential difference exists across it. 2. Both of the bird's feet rest on the same wire, a very short distance apart. 3. That short length of good conductor has almost no resistance, so almost no potential difference develops across it. 4. With effectively no potential difference, essentially no current passes through the bird. 5. The wire is carrying current the whole time, and feathers are not the reason; a bird touching a second wire or the ground would be killed. _Source: NECTA ACSEE 2023 Physics 131/1, Question 8: Current Electricity_