There are two main categories of tics: Motor tics and Vocal tics.
Motor tics are sudden repetitive movements of the muscles of the body that occur repeatedly.
Vocal tics are in the muscles that control speech and cause involuntary sounds.
Most children develop an eye tic first. Other tics develop shortly afterwards with the intensity increasing during early adolescence. Tics can be embarrassing and even painful. Tics tend to take place less during sleep and more in times when the child is under stress. They can also increase when a child is sick or suffering from allergy symptoms.