Puberty mystery solved.
D000293:Adolescent; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003624:Darkness; D005260:Female; D006801:Humans; D007223:Infant; D008027:Light; D008297:Male; D008550:Melatonin / Q000096:biosynthesis* / Q000502:physiology; D010870:Pineal Gland / Q000378:metabolism*; D011627:Puberty; D051381:Rats; D012890:Sleep / Q000502:physiology
D008550:Melatonin