jafary92 added a post in a topic
It's very easy Dear Wolfgang...
Look at it's ears...
If you can see it's ears outside then it gives birth... e.g Humans, Goat, Cow etc. and it it's ears are inside then it lays eggs...Fish, Hen etc.
It's a historical puzzle. Couple of centuries ago same question was put to Ali ibn Abe Talib and I have quoted his answer.
Thanks n Regards.