Whether you’ve owned betta fish your entire life or just recently started keeping them, at some point you’ll wonder or be asked the question: Why do betta fish fight?
There are a bunch of reasons why these pugnacious fish fight each other, but the history behind why betta fish are so aggressive dates back centuries. Betta’s were originally discovered in Southeast Asia in the 1800s. They were brought from their natural habitat in rice paddies and puddles, back to local towns by those working in the fields.
The betta fish and their aggression led to keepers fighting them, betting on the matches, and specifically breeding them for increased aggression. Matches became so widespread the King of Siam regulated these fights by taxing them. This genetic aggression still exists today.
Fighting Myth
Betta fish will not always fight to the absolute death. Most of the time they won’t even get close to that point, unless they’ve been selectively bred for aggression or are trapped in a small tank with nowhere for the less dominant betta to hide. This is especially true for betta splendens or the most common betta’s sold as pets.
Bettas will often damage their opponents scales, gills and tails by nipping and thrashing about. Those injuries, along with infections caused by stress, could, however, kill a betta after fighting. Deliberately making betta fish fight is cruel.
Why Do Male Bettas Fight Each Other?
Male betta fish fight each other because they are incredibly territorial. In the wild, bettas have miles of rivers and paddies to swim through when it’s not drought season. When one male enters another’s territory, the two may show aggression, but a fight may not happen with plenty of room to retreat.
During a fight, the two male bettas will fan out their fins and puff out their gills (flaring) to make themselves look twice as big. This act is done to intimidate and scare off the opponent. If that doesn’t work, they’ll nip at each other until one of the two retreats.
In a tank with no plants or other places to hide, it’s inhumane, to leave them in a tank together. NEVER put two males together without a partition separating them and their visibility to one another.
Male bettas will also fight for food. Betta fish will typically eat as much as you can feed them in captivity. In the wild, however, they have to either find or hunt down their food to survive. In those scenarios, when two males come together, there is no pack mentality, but simply a need to survive.
Males will also fight each other to protect their nests and eggs. When a male betta is ready to mate, he’ll blow a bunch of bubbles on the water’s surface creating what is called a bubble nest. Once his masterpiece is complete, he’ll wait for a female to come along and notice. Any threat to his chances at reproduction will ignite his protective instincts.
Do Female Bettas Fight Each Other?
Females are generally less aggressive than their male counterparts, but they can still be very territorial and will fight one another. They can cohabitate peacefully in groups of female betta fish, known as sororities. Females will generally be aggressive with other females for a little while in a sorority until a natural pecking order is established.
For example, in a 20-gallon tank with 9 female betta fish, one will establish herself as the alpha and the others will submit to her and form smaller packs of their own. Provided no new betta fish are added, disrupting the ecosystem, they will likely live peacefully without incident.
When creating a sorority of females, it’s best to have several in the group and plenty of space for them. A sorority must contain at least 4-5 females. Some females may still be too aggressive for the sorority life.
Larger habitats are best, allowing each betta enough room to claim her own space. Dense plants and hideouts provide betta fish with a safe spot to hide from bullying and to relieve stress. Never add a male to a sorority tank.
Why Do Male and Females Fight Each Other?
Male and female betta fish will fight with each other too. They should never be housed together except during mating and separated immediately after. It’s common for females, for example, to eat the eggs during spawning, so a male will chase off and defend against this behavior.
Males are the ones who place the eggs in the nest and care for them until hatching. They will do whatever it takes to protect their offspring.
Males and females generally fight for the same reasons males fight males and females quarrel with other females. They are territorial fighting fish and don’t cohabitate well with each other.
How Long Do Betta Fish Fight?
If two male bettas find each other in the wild, both will fan out their fins and puff out their gills to look as large as possible. If that doesn’t scare one of them away, the two will nip at each other until one decides to retreat. In most cases, a betta fish fight may last a couple minutes or end immediately.
Fights will last much longer in bettas that have been selectively bred for aggression and usually end with one betta either very injured or dead. Reminder, this is animal cruelty and should never be done in captivity.
Do Bettas Fight Other Fish?
Male and female betta fish are usually kept in small containers at pet stores because of their territorial aggression. These temporary containers are meant to isolate them from each other and other fish. Every betta fish has a different personality and level of aggression. They are also perfectly content living on their own with the right care.
Bettas will fight other fish if:
- The tank is too small for a community ecosystem
- There are not enough spaces to hide
- The other fish resembles a betta fish
- The other fish is brightly colored
- The other fish has long fins
- The other fish is aggressive too
Tank mates should be avoided for inexperienced keepers, but if you want to learn more, visit our tank mate recommendation page.
Avoid tanks smaller than 10 gallons for a community tank with other fish species. You need to provide enough space for everyone to cohabitate without aggravation and overcrowding.
Hi Bryan, I’ve been keeping fish for about 20 years. I’ve had everything from ocros (please forgive my spellng). to rainbow fish. About two years ago i got 4-5 sailfin mollies, I now have at least 20 fish, I want to get most of them all males or all females. In the mean time I got a couple of rainbow fish. I bought new decorations and hidy spots. Everyone is getting along very well, by the way I have a 55 gallon tank. I heard somewhere you could add 1 or 2 bettas they are so beautiful. I wanted to get one more, do you think they’d be ok? I have a dark blue one, id like to get bright gold one or deep red.
Thanks,
Linda
Hey Linda, 20 years that’s awesome! A 55-gallon tank is large and if you have it setup with lots of plants and hiding spaces, it’s possible but not a great idea in my opinion. It really depends on the temperament of each fish and betta. You could try it out while monitoring it very closely and keeping a separate tank or cup close by in case you needed to remove one of them fast. You could also consider splitting the tank in half with a divider so that each side has 22.5gallons and could have a betta fish on each without them coming into contact with one another.
I have had 4 male bettas in the 55-gallon for over 2 years with other species as well. They have been together so long they protect one another it is a beautiful thing. They have never fought over food or over territory. I got all of them at the same time and they were very young, I don’t think even an inch long since day one they have teamed up against the rest of the community.
Hi Bryan!!
My friends and I have been housing Betta fish for a whole 3 days!! We used some of the info on this site for our taxis experiment. We were wondering what your last name is so we can properly site your enthusiasm on our presentation please let me know soon, (in the next day). Your website has been extremely helpful to Betta fish enthusiasts like ourselves!!
Hello, I was wondering, I just got a tank that is 10 gallons and I was wondering if it would be fine I put in 4 female Bettas, I don’t want the to quarrel so I had to ask a expert, also if I get them, how can I tell if one is aggressive before I get it?
4 is the minimum for a sorority tank, so you should be okay. You may need to add one more, but only time and careful watching will tell you that. Telling if they are aggressive during a purchase is not completely possible, it depends how they react in the presence of others in your habitat. I’ve had some that are completely docile on their own and extremely aggressive with a tank mate.
Hello 🙂 Thank you for making this article. I bought my first betta fish today (probably going to name him Ippo or after a famous historical figure) and my uncle insists that I buy him a companion. Now I can tell him exactly why I must not 🙂
Is there any chance that you could create a habitat of multiple males? I see that you have mentioned a sorority is possible. If there is a collective of males (if ever possible,) would that collective be called a fraternity?
Clever naming there Ka-Lai, however, no a fraternity or a collective habitat of males is not possible. You could use a divider system to house males in the same tank (example: 2 males in a divided 10-gallon tank), but they wouldn’t be able to interact with one-another and should not be able to see one-another either.
I had a beta fish named Sushi in a 10 gallon tank with some neons and mollies , all got along fine but my algae eater actually killed Sushi .
I have two betta fish currently. One is named The Dark Knight (blue) and the other Sophia (orange). I don’t know how to tell if Bettas are male or female. I have them in separate tanks. I’m starting to think Sophia is a dude. If so I will call him Stephon.
You can read the anatomy page which will tell you how to differentiate the two sexes.