Nest Box help from the Eggsperts please?

[Mutt Farm]

I have a couple questions. 3 BO's 19.5 weeks, 3 EE's 18 weeks, the rest are younger. No eggs. Nest box has been in the coop for 1 week, Timothy hay bedding, fake eggs in 2 boxes. Chickens don't seem even slightly interested in the boxes. Boxes are on 2 cinder blocks, so say 20 in off the ground. I painted the box white, inside and out.
Questions:
Too young still? Am I inpatient?
Can chickens keep an egg inside and not lay it?
Is the box too high?
Do I need to paint the inside dark?
Thanks for any help, here's a pic of the box. It's darker inside the coop...

 

[ChickenCanoe]

You are impatient, as are we all. It is likely too soon.
20" is probably OK. I have mine about 12".
I would likely close off those holes in the back because they may make the nests too light.

They look good though.

 

[Mutt Farm]

You are impatient, as are we all. It is likely too soon.
20" is probably OK. I have mine about 12".
I would likely close off those holes in the back because they may make the nests too light.

They look good though.

Oh thank you. I can take 1 block out? I'm in Inland So Cal, so it gets VERY hot here May - Oct (95-100+). I was worried about ventilation, so I drilled holes. Do you think I should paint the inside darker?

 

[Percheron chick]

Darker is more private and inviting.

 

[ChickenCanoe]

If you paint the inside darker that may allow you to keep the holes open for ventilation. A lot depends on the breeds you chose and how heat tolerant they are.
BOs and EEs are very cold hardy. Mediterranean breeds would probably fare better in So. CA..

ETA
Once they get used to using a space it won't really matter.
I have one flock that uses a 5 gallon white bucket as a nest box.

 

[Mutt Farm]

If you paint the inside darker that may allow you to keep the holes open for ventilation. A lot depends on the breeds you chose and how heat tolerant they are.
BOs and EEs are very cold hardy. Mediterranean breeds would probably fare better in So. CA..

ETA
Once they get used to using a space it won't really matter.
I have one flock that uses a 5 gallon white bucket as a nest box.

I kinda goofed there. I focused on cute and friendly, not flighty. I have 15 total. Orphs, EE's Marans, Wyandottes, and a Deleware. I have a big fan and deep shade for them. Painting the inside of the box tomorrow. Can chickens not lay if they don't find a spot they like? Thank you for replying. I really appreciate the advice.

 

[Percheron chick]

They will find a spot that is of their liking. It's often not what you provide or where you can find them.