An involuntary repeated movement of groups of muscles resulting in eye-blinking, shoulder-shrugging, facial grimaces, sniffing, tongue clucking, coughing, throat-clearing, or sighing. Habit spasms are most often seen in childhood, and when the cause is not due to copying an adult, which is frequently the case, then it is due to nervous tension. Studies in Britain and Scandinavia have revealed that conflict in the home is the main precipitating factor, but even animals suffer from tics or habit spasms. Chickens kept in egg-laying batteries develop a head-shaking movement which disappears when they are allowed to roam free, and bears and other animals confined in cages display head-bobbing or other recurrent movements which stop when the animal is allowed more space. Treatment of habit spasms in children is not easy, for drugs are quite useless and scolding the child only makes the habit worse. The primary fault lies with the parents and the home environment, and some parents will not accept that it is their own nervous irritability which causes the child to be nervous and insecure. When parents do accept this explanation and submit to treatment for themselves, many habit spasms in children disappear automatically.