Bettas can indeed have tank mates...depending on the betta, some are aggressive, some are more docile. However I believe any type of schooling fish are not an option, unless they are bottom dwellers. Like mentioned, Cory cats are perfect for most bettas, but you should have a shoal of at least 6 and like mentioned, a ten gallon is slightly too small (with a betta,) but I won't say it's its irresponsible to do so....I did it when I first started the hobby, though I probably wouldn't do it again. I slightly agree with others, if you're not super adamant about keeping tank mates with a betta, then just don't do it...but you can. Also keep in mind that your betta may seem to get along great with a tank mate(s), and may snap at any point, a month later or two years later. Hence why I'd recommend just not doing it and consider some cool snails or something....but again, I would not consider it a terrible and irresponsible decision....and have a backup plan and time to observe during introduction. Your betta may just not like ANYTHING.
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