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Why Do Betta Fish Fight Each Other? What You Need to Know!

Lindsey Stanton Profile Picture

By Lindsey Stanton

2 betta fish in tank

Given the name betta fish are commonly known by – Siamese fighting fish – it’s no surprise they fight each other. But, have you ever wondered why they do it?

Of course, we can’t ask them what their problem is, but experts do have a pretty good idea on the reasons.

In this short article, we’re going to look into the question: Why do betta fish fight?

We’re going to explore the murky depths of betta aggression, finding out why they fight one another and whether they’re always aggressive, or only selectively so under certain conditions.

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Why Do Betta Fish Fight Each Other?

They are extremely territorial, so they fight one another to protect the space they perceive to be their own. Males, especially, would need to stake out their territory to gain a mate.

But, other fish can be territorial, and most of them aren’t as aggressive as betta, so what’s going on there?

Well, betta fish are native to Southeast Asia where they live in quite harsh conditions in paddy fields, muddy ditches, slow-moving streams and areas of stagnant water. It’s possible that, due to these less than ideal conditions, there was more competition for food and territory, and so they evolved to become more aggressive.

There’s also the fact that, over the years, they have been bred to be aggressive, especially back in the days when pitting two betta against one another for sport was common. While few breeders breed for aggression today, there may be vestiges of these aggressive traits still lurking in their genome.

paradise betta
Image Credit: lmstevendesign, Pixabay

Is it Ever Safe to House More Than One Betta Together?

Named after “The Bettah” – an ancient clan of warriors – you can be certain that betta fish are avid fighters.

So, is it ever safe to keep more than one together? The short answer: No!

Males will fight to the death. In fact, they’re so aggressive that hosting and betting on betta fights was extremely popular in the fish’s native Thailand a couple of hundred years ago. So, two or more males should never be housed together.

Some people believe that females are less aggressive and are fine to keep together. However, we wouldn’t recommend it.

While females are less aggressive than their male counterparts, they do still flare and show other signs of aggression. It’s not nearly as common as when two males are kept together, but pairs of females in the same tank have been known to fight to the death. Even if one doesn’t kill the other, they’re likely to chase each other, nip and generally stress each other out.

As for keeping a male with a female, never attempt this unless the pair are both ready to breed. Just be sure to remove the female directly after spawning. Even then, there can be injuries and even deaths, so make sure you carefully supervise the pair.

Two betta fish facing each other, isolated on black
Image Credit: Stock4289, Shutterstock

Do They Fish Fight with Other Species?

They fight with one another, but do they fight with other species? Well, that depends on the species!

Betta aren’t nearly as aggressive with other types of fish as they are with each other and, in fact, can live quite happily in community tanks if you carefully choose the species they live with.

If you do decide to house a betta fish in a community tank, you’ll need a 10-gallon aquarium at the very least, but the larger the better. The more space there is, the less likely your betta is to see the other fish as competition.

It’s preferable to add a betta to an established tank, rather than the other way around. This way, they won’t feel so much like the other fish are taking over his territory.

You’ll also need to carefully select the other fish in the tank, but more on that below.

Multi color Siamese fighting fish(Rosetail)(halfmoon),fighting fish,Betta splendens,on nature background
Image Credit: panpilai paipa, Shutterstock

Compatible Betta Tank Mates

If you want to know which kinds of fish can live in a community tank with a betta, check out this handy video.


The simple truth is that betta fight each other because they’re territorial.

As such, you should never house more than one in the same tank. You can, however, keep a single betta in a community aquarium with peaceful fish, as long as you make sure there’s enough space.

Happy fish keeping!

Featured Image Credit: panpilai paipa, Shutterstock

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