How do birds sit on electric wires?

How do birds sit on electric wires without getting hurt, why does hot weather cause nose bleeds, how do probiotics treat vaginal thrush, is there a cure for retinitis pigmentosa, are the any solutions to the problems caused by human activity and what can you do to lessen your asthma? Plus, Australian scientists have discovered evidence of the first life on earth. Like this podcast? Please help us by supporting the Naked Scientists