Okay basically don't keep a male with females, if you want females (only) together atleast more than 2 because the aggression.
From my knowledge they
don't explode, i had a female that had a hole in her stomach before, am not sure why that happens but it does
Please don't be rude to other users here, i know am no moderator or anything hugely important but am pretty known here. people learn from mistakes, so did i many times
Sorry for the lost of your female though.
BTW there
is a way of keeping ONE male in a sorority, am not really known to it. but a user does do that here s/he is professional so thats why no one gives her/him issue's with it. Aslong as you know what your doing, and really full of knowledge of the aggression of betta's people wouldn't get worried