First Eggs!

[GageeNC]

Congratulations! I have 4 buff orpingtons, 2 brahma that are at least 31 weeks old on Dec 5th. They have not laid any eggs! (I'm sure, not free range—yet. Good coop and run.) I started feeding layer feed at about 15 weeks, I have a golf ball on their nest boxes. The only thing I haven't done (after often reading tips/suggestions) is add a light. I have one ready but was torn on adding hear to the coop or not. I waited so they would naturally prepare for winter. We live in the NC mountains the Temps can drop below zero, but typically the low in January is around 22.
I've started joking that they are just spoiled pets that are just too prissy to lay an egg.. Lol. (Have ducks too, same age, no eggs!!! 3 kakhis (1 is drake) & 2 fawn & white runners.)
Guess I'll add a light. Looks like my only other option.