Tippytrampoline
Aquarium Advice Activist
In my personal experience, while my zebra danios never gave any other species in my tank any trouble, I had two males and two females (randomly picked) and the dominant male harassed the submissive male, to the point where he wouldn't let it school or eat, and he eventually died. He then herded the females so aggressively that they stressed to the point of not eating, and they eventually died as well. I'm not sure if that was just a fluke or what, but it may be something to consider, that long term just two danios might not work out unless you can perhaps be sure they're both female? That'd probably be an okay estimation. But done quote me on that, because since my last experience, I've avoided danios, and stuck to more passive barbs and tetras.