Betsy probably killed her boyfriend named George, When you wasn't looking,
For the lack of george to beat up on she then turned her attention to your other fish,
Females can be far more aggressive then males in many instances.
I was at Walmart just the other day, A lady was there with her small son and I heard them say to the lady they'd take that male, Then I heard them mention a friend, a female was settled on, I couldn't resist, I stepped up and stated talking, There son had a small bowl and the lady there actually told them it was safe to add a female, Well I kinda unloaded on them just how wrong they were, The mumma quickly set the female back and thanked me, The attending walmart employee kept saying "thats not what we are told" I point blank said. "Well you were told wrong and if you cared about these fish you'd do some of your own research before you mis guided yet another innocent child into seeing their fishy die needlessly!,
Fishy dead, What happened mummy?