If u think egg development is more than 2 days apart, here is what i do: As the first chicks hatch, after they are dry and on their feet, separate and place them into a temporary chick brooder with a heat lamp, food and water. Unless u do this, the first chicks will get impatient and hungry, & the broody will leave the unhatched eggs to tend to the chicks. If possible, put the brooder in a separate place so the broody cant see or hear them while she is still hatching. Because the broody does "talk" to the chicks even while they are still inside their eggs, so they will know their mothers unique "voice." When all viable eggs have hatched, put the older chicks u separated back with the broody and younger chicks. Do this at night, in pitch black darkness, using a dim flashlight. U dont want the broody to see the older chicks at all until the next morning. The older chicks will snuggle under hen along with the younger chicks, & the next morn she should accept them all. The other most important thing is dont let the broody get a good look at the newer hatches until u have put the older chicks back with her again. Otherwise she may reject the older unfamiliar chicks. Do u have any idea how many days apart the developing eggs are? The above plan can be sucessful even if many days apart. Just critical that the hen doesnt see the newer hatched chicks, think her clutch is complete, & then reject the older "intruders." I have followed the above steps several times when an egg developed/hatched a couple days after the first hatchee. It has always worked for me.
