Odd behaviors can refer to a variety of unusual or abnormal behaviors, such as TICS. TICS are sudden, repetitive movements or vocalizations that are often associated with Tourette Syndrome, a neurological disorder. People with TICS may make facial expressions, blink their eyes, or jerk their head or shoulders. They may also make noises such as grunting, throat-clearing, or sniffing. TICS can be mild or severe, and can interfere with daily activities.