I know from the information that I could find that you're not supposed to use pine and cedar in a frog enviroment, and that oak is kind of iffy. I just needed to know what woods are safe. I have a hybrid poplar and a few hickories in my yard, and my back yard if very wooded so I have woods like tulip poplars sweetgums and a sycamore. Can I use any of those? Thanks muches!