Hens roosting outside?

[BYchicks4us]

Needing help from the knowledge pool here......
I have 4 hens that share a 4x8 coop. The roosting bar in the coop is a half of a 5 ft ladder on an angle from one was to the other (4ft). Two of the hens seem to be roosting outside on another ladder of similar size. Is it normal and/or alright for them to do that or do I need to make them go inside????

It's warm here in Michigan right now so I don't want to 'lock' them in for a few days.
And I don't recall them sleeping outside until a week or so ago. Two of the hens have just started laying -if that matters...but not the two outside, that is one of each breed.

 

[Den in Penn]

How secure from predators are they out there? That is the main reason they should sleep in the coop. A ladder isn't very wide they may have had a tussle over the top and those two lost.

 

[BYchicks4us]

The run is completely covered w/ hardware cloth...you may be right on the space issue. I looked at other coop designs before we built it and saw the ladder idea...I figured they would take different rungs. Although it does look like they roost on the top bar in the coop and they are on the top bar in the run. Thanks ! ..I will try and revamp things.