I recently had made a thread in the 'what gender/breed' thread about a chicken I rescued, only for it to be killed by some unknown predator (which I assume was a fox or weasel perhaps), and some kind folks on that thread suggested I post pictures of my chicken run/pen (I call it both) so that I could perhaps have some of y'all take a look and tell me if there are ways I can improve this pen, to protect against predators or just improve it in general!
I raise and breed a small flock of bantam chickens, currently two roosters and two hens, but hopefully with two little ones hatching out soon. They used to all stay in this pen I and my family build, made mostly of chicken wire and bamboo stalks. It's study, has survived terrible storms, and does a good job of keeping the chickens in, except for one bantam hen I have who somehow always manages to get out. I have no clue how; I don't see gaps in the wire but there must be somewhere. My chickens, the bantam flock and two standard hens I rescued, all lived there for about a year with no problem after we first built it, but it's like once one predator attacked, the attacks just kept coming. I lost one standard hen and a bantam hen to something coming in and killing and eating them, and another to mysteriously drop dead inside the pen -- I'm not entirely unconvinced it was something that came in and killed her, but just didn't eat her. She was in great health. And of course, there was the last chicken I rescued who I had in that pen for only two days before something ate it. I've had my bantams in a dog kennel and a rabbit run further inside the backyard, to keep them safe, and the only reason the last chicken was in the pen I built was because there was nowhere safer to keep it yet.
I miss having my chickens in the run that was made just for them (not to mention my dogs need their kennel back!) so I would love to know how I can make it safer for the little feathered ones. Right now, it's made of just regular chicken wire on all sides and the top, but there's no proper roof, aside from the shade of the tree.
(Click the photos to see them larger!)

This is the view approaching the pen, where you can see most of it except for the part on the right. It's one big pen that has two sections; the left one is bigger. There used to be a second door inside that separated the two sections but it has fallen down. This left part is less crowded, and has a five-gallon bucket lying over as a nest box (the chickens love using it), as well as some proper nest boxes we built. In the corner are some bamboo sticks running through the wire to make roosting poles, which they sleep on every night when they're in there. The door is where you see the metal sheet along the bottom half, and it's closed and secured with a bungee cord, then something usually pushed against the bottom of the door to hold it further closed.

This is the right half; the vault-turned-dog house isn't part of the run if that's unclear, but the little brown doghouse is.

Here's the view when you stand in the doorway and look to the left portion of the run. You can see the nesting boxes, and through the plants that have grown in since the bantams lived there, you can see the roosting poles.

Here's from inside the pen, through the second doorway and into the right half of the run. The chickens would get in the doghouse when it rained, and the material hanging down was a tarp that offered more shelter, but has been torn up by storms. Since this is the part of the run that's closest to the woods behind my house, there's those metal sheets as well as hardware cloth (I believe it's called) reinforcing the bottom of the chicken wire. (The green wire is what their feeder hung on.)

This is a view of the lattice and what used to be the tarp that hung lay above it to offer shelter. The chickens also fly up there to sit sometimes. This is the part of the roof I'm worried about -- that pole in the back fell down once but I got zip-ties and closed up the gaps the best I could, but I'm worried this still isn't safe enough.

This is also in the right half of the pen, a nesting box nailed to the tree. The wooden post to the left of the tree makes up part of the doorway inside the pen that leads out to the left portion.

And this is a shot of the roof; it's not too great because of the lighting but you can get a basic idea of how it's constructed.
So what do y'all think? Should I reinforce the roof perhaps, or focus on the sides? How do my nesting boxes and other materials inside look, and is there anything else I could add to make the chickens safer and happier?
I raise and breed a small flock of bantam chickens, currently two roosters and two hens, but hopefully with two little ones hatching out soon. They used to all stay in this pen I and my family build, made mostly of chicken wire and bamboo stalks. It's study, has survived terrible storms, and does a good job of keeping the chickens in, except for one bantam hen I have who somehow always manages to get out. I have no clue how; I don't see gaps in the wire but there must be somewhere. My chickens, the bantam flock and two standard hens I rescued, all lived there for about a year with no problem after we first built it, but it's like once one predator attacked, the attacks just kept coming. I lost one standard hen and a bantam hen to something coming in and killing and eating them, and another to mysteriously drop dead inside the pen -- I'm not entirely unconvinced it was something that came in and killed her, but just didn't eat her. She was in great health. And of course, there was the last chicken I rescued who I had in that pen for only two days before something ate it. I've had my bantams in a dog kennel and a rabbit run further inside the backyard, to keep them safe, and the only reason the last chicken was in the pen I built was because there was nowhere safer to keep it yet.
I miss having my chickens in the run that was made just for them (not to mention my dogs need their kennel back!) so I would love to know how I can make it safer for the little feathered ones. Right now, it's made of just regular chicken wire on all sides and the top, but there's no proper roof, aside from the shade of the tree.
(Click the photos to see them larger!)
This is the view approaching the pen, where you can see most of it except for the part on the right. It's one big pen that has two sections; the left one is bigger. There used to be a second door inside that separated the two sections but it has fallen down. This left part is less crowded, and has a five-gallon bucket lying over as a nest box (the chickens love using it), as well as some proper nest boxes we built. In the corner are some bamboo sticks running through the wire to make roosting poles, which they sleep on every night when they're in there. The door is where you see the metal sheet along the bottom half, and it's closed and secured with a bungee cord, then something usually pushed against the bottom of the door to hold it further closed.
This is the right half; the vault-turned-dog house isn't part of the run if that's unclear, but the little brown doghouse is.
Here's the view when you stand in the doorway and look to the left portion of the run. You can see the nesting boxes, and through the plants that have grown in since the bantams lived there, you can see the roosting poles.
Here's from inside the pen, through the second doorway and into the right half of the run. The chickens would get in the doghouse when it rained, and the material hanging down was a tarp that offered more shelter, but has been torn up by storms. Since this is the part of the run that's closest to the woods behind my house, there's those metal sheets as well as hardware cloth (I believe it's called) reinforcing the bottom of the chicken wire. (The green wire is what their feeder hung on.)
This is a view of the lattice and what used to be the tarp that hung lay above it to offer shelter. The chickens also fly up there to sit sometimes. This is the part of the roof I'm worried about -- that pole in the back fell down once but I got zip-ties and closed up the gaps the best I could, but I'm worried this still isn't safe enough.
This is also in the right half of the pen, a nesting box nailed to the tree. The wooden post to the left of the tree makes up part of the doorway inside the pen that leads out to the left portion.
And this is a shot of the roof; it's not too great because of the lighting but you can get a basic idea of how it's constructed.
So what do y'all think? Should I reinforce the roof perhaps, or focus on the sides? How do my nesting boxes and other materials inside look, and is there anything else I could add to make the chickens safer and happier?