Habit Spasms -- See Tic disorders Here are entered works on involuntary, sudden, rapid, recurrent, nonrhythmic, movements or vocalizations. Works on intentional, repetitive, non-spasmodic behaviors that serve no constructive, socially acceptable purpose are entered under Stereotyped behavior (Psychiatry).
Habitable Planets -- See Also Exobiology Here are entered works on the study of processes occurring in outer space that are relevant to biology, especially the origin and evolution of life. Works on the biology of humans or other earth life while in outer space are entered under Space biology. Works on life indigenous to outer space are entered under Life on other planets. Works on the prospective use of the science of anthropology in dealing with intelligent beings in outer space, or establishing earth colonies on extraterrestrial bodies, are entered under Extraterrestrial anthropology.