Next time when you use a piece of wood from the wild I would treat it. There are two methods I would recommend and I've used both, but only one is really necessary. I've done both and my logs have no issues with mold.

You can soak it in bleach for 24 hours, then fresh water for 24 hrs, changing the water every 4-6 hours and then let it air dry for another 24 hours.

If you want you can also bake it at 150F for 2-4 hours. Then air cool for 24 hours, remember the core will be hotter than the exterior of the log.

Also on the DIY cage. Would love to have a monitor in the future.