From the look of the picture, it seems as though the cage is sitting directly on your carpet. Is this so? If it is, you're going to need to raise it up at least a 1/4" off the carpet if you're using a UTH. I use a rubber furniture foot at each corner of my cages to lift it off the counter top. They work well. I can post a pic of it if you want. The UTH needs to breath and it could overheat and start a fire if it's resting on the carpet. If you aren't using a UTH though, then never mind, lol...

Also, young boas in particular like to climb. I would add a branch or two. And even though they need higher humidity, substrate that is perpetually wet can cause mold to grow and/or scale rot. Cover your screen top with wax paper or foil to hold in humidity and you'll be better off. You might even find that the moss isn't necessary and coco fiber or cypress mulch will do fine. I use cypress mulch for my BP and lightly misting every 2-3 days keeps humidity at about 70% easily (she's in a glass tank with a screen top covered with wax paper).

Hope this helps!