[Graybeard58]

It is only when the little beasts are touching the wire and, say a power pole

I kind of understood that but they have to touch both every time they get on the wire don't they? Or do they climb to the top of the pole and leap to the wire without touching both at the same time?

I suspect that it's because of the insulation you mentioned that they don't get shocked every time

[YankeeinOkieville]

"Or do they climb to the top of the pole and leap to the wire without touching both at the same time"

Sometimes this is the case. Have you ever seen them run? Quite often all 4 legs are off the ground at once. Or climb a tree or fence post? the first step is often a hop to get onto the vertical surface. As for getting from the pole to the wire, even if they step (rather than hop) onto the wire, those wires that go through neighborhoods are covered with insulation. There's a little break in the insulation where wires that run to individual buildings connect into the supply line at the pole. The animals would have to touch the small bare area of the wire and the pole at the same time to complete the circuit and get zapped.