Are My Chickens Afraid of the Dark?

[squickfall]

I have 27 chicks that are 2 months old. They have been in the coop for a month with a heat lamp (I live in northern BC). I kept them in the coop for a week so they could get adjusted. Now they get access to their run from 5pm to 10pm for the last 3 weeks. All was well until I removed the heat lamp a week ago. They refuse to go into the coop at night and once I manually got each bird inside they all plied on top of each other in a corner, I'm taking about chicken on top of chicken sometimes four high. I panicked and started to separate them with no relief they just came back and tried to get on top of each other. I quickly put the heat lamp back up and at the first sight of light they stopped the pile up and acted as if nothing was wrong? So are my chickens afraid of the dark? What do I do? I have no power to the coop, I have 3 extension cords from the house to the coop, so I need to fix this? Please help what did I do wrong and how do I fix it?

BIG THANKS

 

[CrazyChickGirl]

Try to get them into the coop well before it is dark, so they have time to relax and find a comfortable sleeping place. Soon they will start going in themselves before dark. I'm guessing its just a little shocking for them right now.