Electricity

The D Space
We've been trying to explain to Rhea the concept of electricity, which for most 4 year olds, is a challenge, but shes coping. Most of our interesting electricty conversations happen in the car:
What makes the lights turn red and green?
Electricity.
Rhea: But How?
Well there are wires in the ground and they turn the lights on and off.
But who turns the light on and off?
Its automatic.
Automatic?
Yeah its just like the lightbulb switch in our house, except this one goes on and off on its own.
(doubtfully) Ok.
Where are we going?
We need to fill some gas..
Why?
Cos the car needs the gas.
Otherwise it will stop?
Yes..
But why do you need it?
Everything needs gas?
A lot of things, like a car, dump truck, aeroplane, choo choo train..basically anything that moves and is not a person.
Even our lawnmower..
So my bicycle needs gas?
(Me Sheepishly) No.