Originally Posted by flakey chick
Water test is only for the very last stage of hatching. Put the egg in a glass of water. If the chick is alive and at all viable, it should feel like it is drowning and struggle. The egg will move.
i've never heard of that. Sounds a bit harsh. Does the chick stand a chance of drowning from the water test?
From my personal experience, i only see the heart beat when the chick is first forming, maybe the first half of incubation. After it fills the egg more, i can't see the heartbeat and i don't see the chick move. i just keep all the eggs that may be viable in the incubator (or under a broody) until a day or two past hatch day. Then i might pick up unhatched eggs, tap on the large end with my fingernail and chirp. If you hear chirping back, someone is in there. If not, generally they are not viable.