How Can I Tell If My Duck Egg Is Fertile?

Put your egg in a cup of water. If it floats, its fertile. -]

The fertile egg will remain viable for almost two weeks. If it is kept in a properly controlled, refrigerated environment, it may last longer. A fertile egg actually begins to deteriorate very quickly; at two weeks you're really pushing it if you want a successful hatch.

You put a light under it and if it is just white it is not fertilized but if you can see black veins and a  black dot it is fertilized but it has to be a few week old

Candle them

You must candle your eggs to see if they are fertile. About 7 days into incubating you can Candle them to see if and veins formed. If so probably fertile. Duckeggs.com has lots of info!

The egg will stay fertile as long as the hens sits on the egg this the only way for the egg to mature.

The egg is fertilized before it is laid. It takes 21 days for a fertilized egg to develop to the point where the chicken hatches. The egg must be incubated for this to occur.

Hi I have duck eggs that are in the incubator then put them in water to see if there alive or not I really don't now because when I put it in the water the tip sunk and half of it was floating. So I wont to now if they were alive. And one more when I candled my egg at first I saw veins the after 2 weeks I saw a big black THING THAT LOOKS LIKE A HEAD OR BODY WHAT DOES THAT MEAN....

If one of the eggs had a duckling inside then the others must too
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Crack open one to see if its fertile they will be a little white attched to the yolk