When the teeth of the comb are about an inch or less away from the stream, the stream will bend toward the comb. Move the comb closer to the stream. Run the comb through your hair several more times. Change the size of the stream by adjusting the faucet. If you have other combs, you can try these to see if some bend the stream more than others.
Static electricity is the accumulation of an electrical charge in an object.
The electrical charge develops when two objects are rubbed against one another. The object that loses the electrons becomes positively charged, while the object that they jump to becomes negatively charged. The nature of the objects has a large effect on how many electrons move. This determines how large an electrical charge accumulates in the objects. Hair and nylon are particularly good at acquiring charge when they are rubbed together.