Hatching a double egg?

[Luke 13V34]

I have seen plenty of doubled yolked eggs, and I was just curious, what happens if you incubate them? Are they mainly infertile or do the young inside just not survive or do you end up with (conjoined) twins?

Also, I have seen hens lay that odd ball "tiny" egg. I had a bantam lay an egg the size of a robins egg. I was wondering, what causes that and are those infertile as well or could you hatch the world's smallest chicken?

Thanks for handling my random questions.

 

[WalnutHill]

I have seen plenty of doubled yolked eggs, and I was just curious, what happens if you incubate them? Are they mainly infertile or do the young inside just not survive or do you end up with (conjoined) twins?

Also, I have seen hens lay that odd ball "tiny" egg. I had a bantam lay an egg the size of a robins egg. I was wondering, what causes that and are those infertile as well or could you hatch the world's smallest chicken?

Thanks for handling my random questions.

As for twins: successful hatches are quite uncommon as often one will die during development which often kills the other. I had a turkey twins go full term but I was on an out of state business trip and they died at hatch time as they were too crowded to move.

The "tiny" eggs are generally not complete eggs, the yolk if any is often just a speck but more often those simply enclose a bit of shed reproductive tissue.

 

[Luke 13V34]

Thanks! I was always curious about those things. It is a shame about the turkeys, that would have been something...