What size tank is he in now? It all depends on the temperament of your individual betta. I know that sometimes people report keeping them with other fish, but I never would, with a male. Had a bad experience many years ago when I didn't know what I was doing. The betta would sneak up to a fish, sidle up close, very slowly, then BOOM! He'd take a bite out of it. I only keep females in a community tank. I have eight, and it works out nicely with many different kinds of fish. Rainbows, balloon mollies, cherry barbs, and angel, dojo loaches. I've noticed a rare female betta will tend to be super bossy, and chase others. I've had to take back two that did that. Otherwise, I've had many female bettas over the last several years, and most are fine in a community tank with nothing that are fin nippers, such as some barbs. You have to be careful in your selection of betta tank mates. I would be much more comfortable with a female betta with your danios, to be honest. Danios are fast, but male bettas are also unpredictable unless you get a mellow, laid back one. You would be taking your chances of finding some ripped apart danios some morning, and that wouldn't be a nice thing to see.