Brush the carpet with a stiff bristled brush or.
Lots of hair on carpet.
Use the dishwashing gloves that happyturtle suggested and rub your hands in a circle in one area on the carpet.
Anyway you need two cups of water and a tablespoon each of white vinegar and dish detergent.
Get a painting roller and wrap it with thick double sided duct tape.
Fill a spray bottle with water.
It d be a lot of work for large areas though.
If you are trying to remove long hair in your carpet you would want to use short deliberate strokes.
Hold like a regular broom but do not push.
Now roll it over your carpet.
The sticky will pull the hair right out.
Spray the carpet lightly to dampen the hair and prime it to clump together.
You can buy one or simply can make one yourself.
Use it by pulling it towards yourself.
It ll take a while to do the whole carpet like that but it balls up the hair and makes it easier to gather.
It works well on carpets.
I have long hair that constantly mucks up my vacuum so i just take scissors to the hair after i ve unplugged the vacuum.
For problem areas i tape together a square of masking tape about a foot 0 3 meters on a side and press that onto the carpet after a stiff brushing.
Add several drops of fabric softener.