Why are they doing this

[babybaits]

How old are they?

They're about 5 months old.

 

[Iluveggers]

Wow... Someone really treats their chickens like royalty.
I'm sure you meant golf balls.

Lol. Yes. Although my chickens do get treated like royalty!

They're about 5 months old.

About time to think about laying the GOLF balls won’t hurt!

 

[rosemarythyme]

If the scratching in the nest box specifically is new behavior, yes that's a sign that they're exploring the nests as potential nesting spots as they get closer to laying.