3 week old chicks not sleeping under brooding plate

[laurenmc40]

I have noticed in the last week or so that 3-4 of my 6 chicks choose to bed down on top of the brooder plate when they go to sleep. I have it set at the highest height setting and the house temp is around 70⁰. Should I be raising it even higher by using blocks or something?

I'm also considering moving them out to the shed where daytime temps are currently in the 60s and 70s and nighttime temps are in the high 40s to low 50s. Would they be fine out there with just their brooder plate?

Sorry for the poor photo quality through the hardware cloth!

 

[DobieLover]

I'd move them out. They should be just fine with the set up as it currently is.
If they are sleeping on top of the plate in the house, they are warm enough at 70.