“Under the influence of material desire, the entity is born sometimes as a demigod, sometimes as a man, sometimes as a beast, as a bird, as a worm, as an aquatic, as a saintly man, as a bug. This is going on. And in all cases the living entity thinks himself to be the master of his circumstances, yet he is under the influence of material nature.” (Shrila Prabhupada, Bhagavad-gita, 13.22 Purport)