Habits are activities that start as repeated actions and then become a part of a person's life. Although many habits are benign, i.e., shopping or doing laundry on certain days, eating meals or bathing at specific times, etc. Some habits can be annoying or physically damaging; nail-biting, knuckle-cracking, etc.
Other habits can be unhealthy or destructive, especially if they rise to the level of being an addiction (smoking, using drugs), or a compulsion (i.e., hair-pulling). Habits can be changed or broken through effort and/or with the help of therapy if they are causing difficulties in everyday life.