Beitzah 6 - A chick
Having discussed an egg laid on a Holiday (Yom Tov), the Talmud turns to a chick that hatched on a Holiday. What is its status, can it be eaten? We have two opinions. One is that it is muktzeh (set aside) - since before it hatched, it was not fit for any use. The other opinion is that it is permitted: if one were to slaughter it, it would become permitted as food - and this permission removes the prohibition of muktzeh.
But why would it be muktzeh? We know that a calf born on a Yom Tov can definitely be eaten, so what is the difference between it and and egg? - The answer would be that the calf was permitted even while inside of its mother - if one slaughtered the mother. This logic obviously does not apply to the chick.
There is also the opinion of Rabbi Eliezer ben Yakov, who says that the chick is prohibited even on a weekday - all the time that it has not opened its eyes. This is because before this time it is not properly a bird but a creepy-crawly, and is prohibited together with other " things that creep upon the earth ."
Art: The Proud Mother Hen and Chicks by John Frederick Herring Snr