I just picked up an emerald crab for my 10g nano and I have so far one toadstool in there. After checking up on him, i noticed he was crawling on my toadstool that was previously opened and now all shrunken up. I also noticed a tiny chunk of my toadstool missing. I am so mad!! I love my little toadstool and this crab just took a bite out of it like it was a cheeseburger! How do I stop this from happening? Should I bring my crab back and exchange for another invert (maybe a diff crab or some hermit crabs?). Attached is a pic before and after of my coral