Join Date: Jul 2014
Location: Massachusetts, US
Ah I'm not an expert, but I put a male guppy in with my female betta, and they did not harm each other, or at least not that I have noticed. Now I'm not completely sure, I have mostly heard neutral answers, but you might get a no from many people.
See since guppies have that same colorful glow, it presents competition to the bettas, and maybe your betta sensed they were females? If they were? That is pretty much all I can say, as my personal experience wasn't bad, but maybe your betta just is more territorial than others.
Kaze~ Male EE
S.I.P: Rocket, Penny, Misty, Comet, Iris, and Katie