Advertisement I am assuming that you should not re-use substrate between Tarantulas, due to them filling it with their web and hair, but would it be bad to re-use it between other inverts that do not web or have hair? I always toss out old T substrate when rehouseing (or use it in the new setups for that same T), but I think in the past I have reused substrate from my scorpions for T's when I was really low. I have not had any problems, but at the same time I dont remember who I did this for. So would this be considered a bad or unhygenic practice? Also, what do you have to do to a hide after it has been used for some time to get it suitable for use by another T? As my slings get larger, their old hides are becoming too small, but I dont think I should throw them away. Oh, also would it be bad to use hides and decorations from reptile tanks in invert, particularly tarantula, enclosures?