New Babies

[Chixnbacn]

What isn't true?

If that egg was from a secret nest your kids found, then clearly it had been laid close to three weeks ago AND either been under a broody hen or in ambient temperatures warm enough for a chick to fully develop.

Collecting eggs (that are freshly laid and haven't been sitting around for unknown amounts of time) regularly will prevent the issue OP is concerned about.

I collect every single day several times a day because we are home nearly 24/7 and we have a ton of hens we dont heat our coop. Think what you like

 

[kattabelly]

I collect every single day several times a day because we are home nearly 24/7 and we have a ton of hens we dont heat our coop. Think what you like

But clearly you didn't collect that egg for the best part of three weeks after it was laid, because the chick had time to develop.

If you don't live somewhere that gets hot enough that eggs could start to develop on their own, then the egg must have been kept warm by either a broody or something other heat source.

Fully formed chicks don't just form inside fertilised eggs overnight. Ever. It's not physically possible, and it's unhelpful to suggest otherwise when someone posts seeking advice or reassurance about exactly that.