Try putting apple cider vinegar in a clear jar. Cover the top with plastic wrap. Use a fork a poke some holes in it. Place by your enclosure not in it.
I have never plugged my holes and my humidity stays around 80 -85%. But I also live in Florida. If your outside humidity is low then I suggest plugging the holes.
There are some netting options. I have a small area for my dogs. I used batting cage nets. They come in all sizes. When I was searching a few years ago they offer lighter netting called bird netting. Might be a good option.