Their humidity requirements do cross over enough to house them together. I have kept my red eyes around 70 percent for years. Now I do give them seasons of dryer times and wetter times depending on the weather in my local area. If it's raining outside I mist them more. If it's a summer and not raining I don't mist as often. Eric...if your Americans are doing fine at 70% then they'll be fine together until Lizzie can get a permanent home for the AGTF. Im just trying to address the immediate life or death issues that we have going on here. I suspect the tank they are in right now as it is set up is on the dry side. Then the fact that they are exposed and possibly having too much light coming in at night could be stressing to the point where they are having health issues. Keeping a AGTF in a small critter keeper is more harmful to him than being in with the Red Eye. The fact that they have come from Petco is a concern because they may have been exposed to different diseases and that's why they should be separated instead of putting them together. But at this point my primary concern is they tank as it is setup right now is not meeting the needs of either frog. That needs to be addressed immediately or Lizzie will continue to lose frogs.