The relationship of the animal ear as it begets or lays eggs:

From knowledge of Imam Ali bin Abi Talib (p.o.h) in animal: someone asked Imam (p.o.h) : How can we know if the animal begets or lays eggs?

Imam (p.o.h) said: If its ears are hidden so it lays eggs and if its ears are apparent so it begets.



From Aywen Al-akbar for-ibn Kuteiba page489