So my husband and I noticed this odd egg shaped cotton like substance in/on our birds nest this afternoon. We both swear it wasn't there this morning, and we don't see anything like it anywhere else in the tank. His guess is a hermit crab shell that hasn't seen the light of day. I personally think it looks more like eggs cause it's more wedged in there but appears now a part of the birds nest. Either way here's some photos, please tell us what you think. Thanks in advance, Marina & Kyle