This experiment requires only a comb and a thin stream of water.
If your faucet can create a thin stream of water you can perform this experiment at the faucet. If it doesn’t, fill a plastic bottle with some water and pierce a tiny hole on the bottom of the bottle, this will create a thin stream of flowing water.
Once you have a thin stream of water, run the comb through your hair quickly. The more you run it through, the stronger the charge on the comb will be. Now bring the comb closer to the stream and watch as the stream of water bends toward the comb.
This whole experiment is possible due to the presence of static electricity (the accumulation of charge on an object). When objects are rubbed together electrons hop from one object onto the other. The object that gains electrons becomes negatively charged and the one that loses electrons becomes positively charged.
When a charged object is brought close to another object it attracts the new object, this is how the comb attracts water.
Tip: It’s easier to produce static electricity in low humidity environments. Humidity causes a layer of moisture to be formed on surfaces which prevent electrons from transferring between objects.
There’s a great video from ‘Jefferson Labs’ that demonstrates this experiment: