Can a chicken lay an egg during the night?

mine lay every time of the day...

 

I have some lay at nite and they are sitting under the roost when i go in in the morning. My older red stars lay mainly during the morning. My other girls seem to lay at all times of the day. i wonder why their clocks are so different of when they lay.

 

I THINK the most common time for laying is mid-day. But I suppose if a hen felt the urge, she would lay anytime the egg is ready...

 

My girls have been laying for a month or so. There is almost always one egg when I let them out at 6 am... sometimes two. Occasionally, whoever laid it doesn't make it to the nest box and the egg is sitting in the poop under the roost.

 

I read somewhere that it takes 26 hours to make an egg so if a chicken lays at 9 am one day, the next day she will lay at 11am, then 1 pm and so on. This seems to be true with mine. And then when it's bedtime, they don't lay during the night and so they miss that day and start over the next morning....

 

My cheekens lay at any hour of the day, and sometimes they will wait in line for the same nesting box. One of my cheekens dropped two eggs on the ground from a high roost when she laid her first and second eggs, then I showed her where to go and she began to lay them in the nesting box.
Now I have a question about cheeken behaviour. I have a little Silkie and she has been sitting on her nest for two days...I am not sure whether she comes out and eats and drinks or not, but the food and water is not 5' from her, so I'm assuming that she sneaks out and snacks. She regularly lays a nice medium-sized egg, but I always retrieve it the same day she lays it, so why does she stay on the nest with nothing to hatch?? Has she gone broody, or could she just be tired of the romancing she has to endure daily? If she has gone broody, and I stick a couple of eggs up under her for her to hatch, will she stay on the nest and hatch them, or might she get off them and refuse to hatch them? Thanks for any opinion on this. Also, if anyone thinks it is a problem of over-romancing, should I separate her for a couple of days so she can get some rest?