One common situation when experiencing static electricity is when you walk across a carpet and then touch a metal object, such as a doorknob, and feel a sudden shock or spark. This occurs because as you walk across the carpet, your body picks up extra electrons from the carpet, giving you a negative charge. When you touch the metal doorknob, the excess electrons on your body flow quickly to the positively charged doorknob, creating a static discharge or spark. Other situations where static electricity may be experienced include rubbing a balloon on a sweater to make it stick to a wall, or getting shocked when touching a computer or electronic device that has built up a static charge.