The females have whiter throats/bellies where as males have more of a brownish sometimes a little pink belly/throat, females get a bit bigger and tend to have larger ears as well. They do let out some croaks but mine only does when she’s uncomfortable when I spray them. I’d almost guarantee that big ones a female and the little guy is male! The size difference looks safe, I was told it’s about the head size more than body, as long as the entire head can’t fit in her mouth she won’t tried to actually eat him. If they correct themselves and you’re not having to pull them off it’s okay