Why a bird does not get electric shock when they sit on electric wire?

Why a bird does not get electric shock when they sit on electric wire?

Usually,when a bird sits on a wire its body touches the wire only and no other thing.Thus no potential difference is created for the current to flow through the bird's body and so the bird doesn't get an electric shock.  Incase the bird would have touched anything else(such as another wire or a nearby wall) at the same time it was sitting on the wire, a potential difference between the two parts of the bird's body (touching two different things)would have been created and it would have got an electric shock. Consider the two terminals of a battery.When we take a wire a connect it to one of the terminals while keeping the other end in the air, no current flows through it.  Now if you connect the two ends of the same wire to opposite ends of the same battery,current will flow through it due to the potential difference between the two ends of the battery.(This can be verified by connecting a bulb to the wire which glows on the account of the current passing through it due to the potential difference).  The same happens in the case of a bird.Usually,when a bird sits on a wire its body touches the wire only and no other thing.Thus no potential difference is created for the current to flow through the bird's body and so the bird doesn't get an electric shock.  Incase the bird would have touched anything else(such as another wire or a nearby wall) at the same time it was sitting on the wire, a potential difference between the two parts of the bird's body (touching two different things)would have been created and it would have got an electric shock.