It is a popular tale that a double yolk egg will have twins. Is this true? If the yolk is the food then why would it create 2 chicks? Will they even hatch? Thanks.
It's similar to fraternal twins in humans, 2 ova released in 1 "package" so yes in theory twins, however getting both to form during incubation can be dicey (somewhere on my bookshelf is a book with statistics from trials, but I'm feeling lazy). Also like in humans, multiple births have a higher rate of complications.
Do a search on here and on youtube and you can see Rebecca helping her twins hatch out of a double yolker. She had two double yolkers and got 3 chicks.
What they said about actual video of twins being helped to hatch is a good way to watch it happen. Quite neat. I love that video. Thing is unfortunately most of the time both twins don't go, one quits. It's quitting eventually kills the other. I've incubated seven double yolks to date, and usually only one twin starts and keeps going, the other starts and fails. I've got one in now that maybe actually going to have both go. It's only day four so candling will be more conclusive next week. Twins cannot hatch by themselves, no room to move and position for hatching in that tiny space, so they're rare and they have to be helped out to make it out. And often the second may have a defect so sometimes one will not survive. While survivors are rare - no it's not impossible.
