Hen walks to her eggs and sitting on them!

[Michael]

ahoba wrote

I can summary your answer to be one word “INSTINCT”. Without “instinct” hen will not sit on her eggs. Am I right?

Not in the way I suspect you want it to. What do you think 'instinct' is?

Also - How much do you know about evolution, natural selection etc?

I posted some links earlier, if you need an understanding. If they don't help, I'll try to find something a bit more simple and straightforward.