Why can't the sparrow shock

When the sparrow stands on the wire, the distance between the legs is very small, so the voltage is very small. The current will not pass from the body to the other leg from one leg, and it will only flow from the wire, so it will not shock.However, if the sparrow places its feet on different wires or grinds my mouth on it, it will cause the current to pass through the body, so that it will die electric shock.Anti -stopping accident.