They are the hard woody kind of fungus. I boiled them until they sank, then baked them for 3 hours. I was a little concerned that they still felt fairly soft afterwards, but after a few days they dried up to their original hard selves. I've since found a huge one nearly the size of my head that I'm going to have to find a use for .
Looks great! This build is a prime example of use of all of the vivaria building topics discussed here on the forums.
Excellent work buddy!
Watching FrogTV because it is better when someone else has to maintain the enclosure!