The Pre'lek are bipedal reptiloids with prehensile head-tentacles. There are two Pre'lek "sexes": neuter and fertile. Fertile Pre'leks, or Pyo'wuu'ka, are divided into three classes according to which fertility cycle they are in. In the nurturing phase, Pyo'wuu'ka suckle and tend to newborn young. The next two cycles are alternating male and female phases (Pyo'wuu'ka are born hermaphroditic). If pregnancy occurs while a Pyo'wuu'ka is female, "she" is "locked" into the female cycle for the entire gestation period. Following birth, the Pyo'wuu'ka enters a brief period of inactivity and ritual seclusion -- the young being taken care of by nurturing phase Pyo'wuu'ka.