How do you know if the bird in the egg is alive?

Question

How do you know if the bird in the egg is alive?

Answer 1

The egg will not have a vibration to it when you gently shake it back and forth.  You could also see if you can see through the shell - hold it up to a bright light.  When our chicken eggs were duds - they felt like they sloshed when you shook them - gently.  The ones with chicks felt more solid.

Answer 2

After about 5-6 days you should be able to candle the egg and see veins if it is fertile.  Just hold it up to a bright flashlight and you should be able to see through the shell.  Don't shake it!