The same thing happened to my green tree frog a couple days ago. She had blue spots above her eyes. She died over night, and the left time I checked on her she was hanging off of her water dish. I found her belly up dead next to the dish the next day. She lived in a 22 gallon 70 degree 55% humidity tank with eco earth and frog moss substrate. In the same tank I had a gray tree frog and other green tree frog. She was about half the size of the other tree frogs. I put her in another tank in case she was playing dead, and I heard a popping noise and her stomach popped like a balloon and deflated. I don't think the other frogs would kill her because they're all females. I used sink water but I have a well and the water isn't chlorinated. Does anybody know what could have happened? Could the blue spots be caused by disease or could they be bruises caused from the other frogs? I don't think green/gray tree frogs are territorial, though.