Free range chickens not going home at night

[cornball]

So, I have had my RIR flock for several months now, been free range nearly the whole time. They are great layers and are very great birds for us. Our only problem with them is that only about two of them return to the coop on their own at night - the others go in the dog house, under the LP tank, or in one of their various other hiding spots. As a result, we have to take half an hour to around an hour and a half every night to find each one and put them in the coop. We have lost 3 chickens to predators simply because they were too well hidden and we were unable to find them after several hours of looking (before sunset, and well into the dark with flashlights). What can we do to encourage them to go to the coop at night?

 

[bobbi-j]

Is your coop large enough that you can keep them locked in there for a week or so, so they will think of it as "home"?

 

[cornball]

Is your coop large enough that you can keep them locked in there for a week or so, so they will think of it as "home"?

Yeah, I had them locked in the coop for a couple of weeks right after I got it finished, and then started free ranging them. Here is a link to the coop I built them: https://www.backyardchickens.com/t/647945/built-my-first-chicken-tractor#post_8741489. Should I lock them up again, you think? Here in Iowa, the winters get cold, and I was planning on closing up the bottom with plywood for the winter and putting a heat lamp in the top of the house to provide light for 14 hrs and also warm the coop. Would locking them up for a time, then letting them out and then locking them up again in a couple of months be detrimental?