betasBettas aren't meant to be in the same tank together; males together like male and male will fight but, though based on my research females together don'twon't. I did research and found out they can be togetherthink the chances of one of them just dying is slim it is. It's possible when you were not paying attentionthat the male could have attacked the female and you didn't notice, and then the female could have got (revenge) or nibbled him back"got revenge," but that is mythat's just a theory.