GENERAL KNOWLEDGE: Admit a person into a society or club through a secret ceremony?

Questions

---------- often sleep for up to fourteen hours a day?

gorillas often sleep for up to ---------- hours a day?

hippopotamuses do ---------- percent of their vocalization under water?

if a frog's mouth is held open for too long the frog will----------?

if monkeys eat too many un-ripe ---------- their tongue and eyes will turn green?