Why is it that squirrels and birds can walk on power lines without getting shocked?

Question

because when we touch powerlines we get shocked just curious

Answer 1

As long as you only touch one wire and don't touch the ground you would be okay.  That is what birds and squirrels are doing.

The problem is that we are always standing on the ground.

Answer 2

Basic electrical theory, namely,  current only flows when a circuit containing a voltage source is completed. Since the bird does not touch any 'ground' point, the circuit (i.e., line, bird, ground/earth), is not completed. Hence no current can flow through its body and therefore it can not suffer an electric shock - fatal or otherwise.  

You, for example, could swing from a high voltage line (assuming you were foolish enough to want to do such a thing!), and as long as you simply dangled your legs in space you would be all right, too -  but if you allowed your feet to touch anything regarded as 'earth'... then it would seriously hurt!!

Answer 3

usually the line is insulated, or the power company put up a "bird line" which is just a piece of wire, with no current running through it and is higher then the other lines (that way birds will land on that one first). The bird/squirrel can only get shocked if it touches 2 wires at the same time, or touches the ground and a wire that isn't insulated. so usually one or both wires are covered by some sort of insulation, ususally rubber.

Answer 4

Because they are not making a "ground", i.e. they are only touching one wire.  If they were to touch both wires at the same time, or one wire while touching the ground, then they would be electrocuted as well.