How can I tell? Can I tell?

[azure_]

If you are trying to hatch your own eggs without a mature rooster, it will not work, when a rooster begins actively mating they are almost certainly fertile.

I'm not currently trying to hatch and won't until he's mature and I have an incubator. I was just wondering

 

[NatJ]

There is no way to check a particular egg for whether it is fertile, and then put that same egg into the incubator.

If you crack an egg and look to see whether it was fertile--you cannot put that one in the incubator.

If you want to see anything useful when candling, you have to incubate it for a week or so first.

It's common to have no fertile eggs (no rooster or rooster too young), or to have all eggs be fertile (rooster mates regularly with all hens).

Sometimes a rooster will have favorite hens that he mates with, but completely ignores some other hens. In that case, the ones he ignores will lay infertile eggs.

A hen only needs to mate once or twice a week to lay fertile eggs all the time--although most roosters make sure it happens a lot more often than that