I know. I think maybe there were no issues with the boys before because the mom was the only breedable female but then once seperated he decided that was his female and his instinct told him to get rid of the other males? I know poor babies
To be honest though I'm glad it happened to me and not someone who went to buy them for pets because as sad as it is, I can kinda accept that these things (though they shouldn't) do happen once in a while. it's heart breaking but I've learned for next time.