I've ordered some long fibered sphagnum moss for my terrarium. Right now the mix is purely peat moss and perlite which is not keeping very wet or humid which is why I ordered the sphagnum. Anyway, I've noticed some very strange looking stuff growing on top of the peat. It's extremely bright green, to where it's almost comical. It grows in little patches around the cage and a little around some red dragons I have. Is this stuff mold? What should I do if it is?