Friends:

If Blinded by Ignorance one takes Animal Rebirth!

Because of greed one is reborn in eggs of geese, doves or as other animals
obsessed by great passion, like also in the womb of a rhinoceros...
Because of ignorance one is reborn in the eggs of insects and worms.
Because of hate one is reborn as snake. Because of pride and obduracy,
one is reborn as lion. Because of arrogance & narcissism one is reborn in
the wombs of donkeys and dogs. If miserly & discontented one creates
rebirth as a monkey. If foulmouthed, faithless & shameless one is reborn
as crow. Those flogging, chaining & injuring elephants, horses, & buffalos
become spiders, scorpions, & stinging insects of cruel character. Those who
are flesh-eating, angry, & fiery are reborn after death as tigers, jackals,
cats, sharks, vultures, wolves & the like. Those who are generous givers,
but angry & cruel become Nāgas = snake-demons  of great iddhi-power...
Any deliberate wrongdoing in thought, speech and/or action can produce
rebirth as animal! Therefore one should always shun all that is wrongdoing...


Animal rebirth induced by cruelty!

Please enjoy study here for details on Rebirth:
http://What-Buddha-Said.net/drops/Rebirth.htm
http://What-Buddha-Said.net/drops/IV/Rare_Rebirth.htm
http://What-Buddha-Said.net/drops/IV/Divine_Rebirth.htm
http://What-Buddha-Said.net/drops/IV/Animal_Rebirth.htm
http://What-Buddha-Said.net/drops/III/Endless_Round.htm
http://What-Buddha-Said.net/drops/IV/Samsaric_Dread.htm
http://What-Buddha-Said.net/drops/IV/The_Minor_Hells.htm
http://What-Buddha-Said.net/drops/III/One_BIG_Family.htm
http://What-Buddha-Said.net/drops/IV/The_Hell_Destiny.htm
http://What-Buddha-Said.net/drops/IV/Five_Destinations.htm
http://What-Buddha-Said.net/drops/IV/The_5_Destinations.htm
http://What-Buddha-Said.net/drops/IV/Kamma_and_Rebirth.htm
http://What-Buddha-Said.net/drops/IV/The_Samsaric_Round.htm
http://What-Buddha-Said.net/drops/IV/Mad_Demon_Rebirth.htm
http://What-Buddha-Said.net/drops/IV/Human_Being_Rebirth.htm
http://What-Buddha-Said.net/drops/IV/Hungry_Ghost_Rebirth.htm
http://What-Buddha-Said.net/drops/III/What_passes_on_by_Rebirth-Linking.htm

Transmigrating into the Animal Realm!

Source (edited extract):
Pañcagatidīpanī  by Ashvaghosa & Saddhammaghosa: 11-12th century AC.
Tr. by Ann A. Hazlewood. Journal of the Pāli Text Society. Vol. XI 1987:
http://www.pariyatti.com/book.cgi?prod_id=132714

Animal Rebirth!