Today I filled a bin with soil, hide outs, rocks, and some plants and grasses. I thought about putting some live moss in some of the corners. What brands are safe for gerbils, and is live moss safe? I have some dried moss for reptiles is there a way that I can re-hydrate that?
You would be best to put the moss in dried - as moss holds water and I always find that in enclosures it creates humidity and makes other substrates go all soggy. It is quite heavy too when fully hydrated and cold to touch (which I can't see as being fun permantently for anyone?).
However if it is just for a run or short term/well-monitored set up - people have used it moistened/live for sure.
It isn't harmful in of itself - so I suppose it is something you can try and see what you think. If in a very well ventilated large enclosure in the sandy/non-absorbant soily side it might be fine - but just like most other things sold for tropical exotics it keeps up the humidity - something gerbils in general need the opposite of.
Your bin sounds totally cool though - I hope they enjoy it!