Hi everyone!

I am new to this forum and a first time frog owner. I currently have three whites tree frogs living in a communal, bio-active vivarium. One of my whites tree frogs suddenly looks bloated and I found it sitting awkwardly hunched over. I'm not sure how to describe it but it was sitting with its back scrunched up so that its belly wasn't touching the ground and its back bones were protruding more so than normal. I have never seen it sit like that and I had just noticed the slight bloating so I wasn't sure if they were correlated? In that same moment I also noticed one of my other whites tree frogs starring at it and then lunged/jumped at it. So I was thinking maybe it was sitting like that as a defense mechanism? I have had these frogs in the same tank for almost a month now and haven't seen or experienced any of them being aggressive towards each other or lunging at each other. Any ideas?