Fishbowl Adviser

Why Do Betta Fish Fight and How to Stop Them

Betta fish are actually known for their aggressive nature and tendency to fight each other. While they are referred to as “Siamese fighting fish” or sometimes “labyrinth fish,” the scientific name for this species is Betta splendens. However, with a proper tank environment and careful considerations, you can avoid a betta fish fight and enjoy your new pets.

Betta fish

Why Do Betta Fish Fight?

There is a reason they are referred to as Siamese Fighting fish and it is because the males are incredibly territorial when they are in the wild. Betta fish have an aggressive nature by default, and it is mainly because males will fight one another for territory and food resources. In the wild, their natural habitat would often be limited with little food resources that they need to fight for and later guard it. And even though an aquarium is not like the wild, it’s still best not to keep multiple male bettas together in the same tank. An aquarium is a small place, and there is no place to retreat, which means that they will fight until death.

Since they are very territorial, betta fish can often fight because of intimidation. Despite their aggressive nature, they are often startled by any movement, especially if it is from fish that have long fins and large tails. Although it is very rare, it’s also worth noting that they can be startled by brighter colors. Another reason for betta fish fighting can be stress that can be caused if there are any changes to the water conditions or their environment. Even changing the aquarium decoration can stress them.

They can also be aggressive after mating season and fight to protect their nests. When a male betta fish wants to mate, he will blow bubbles on the surface of the water and create a bubble nest and wait for the female to notice the bubble nest. Because they create the nests, males are also tasked with protecting them, so if another male fish approaches the nest, their instinct would kick in and they will fight to defend the eggs.

Even though male betta fish are aggressive towards each other, they can also fight female bettas as well. During the courtship between males and females, there can be some gill and fin flaring, but it can also mean that there will be a fish fight. Female betta can get very aggressive, especially in community tanks, until there is an established order. Because of that, it’s best not to keep male and female betta fish together, and it might be best not to put them with other species as well – especially if they are known for not getting along at all.

How Do Betta Fish Fight?

If we’re talking about territorial fighting, there is a clear ritual that leads to a fight. Before the fight starts, there is some intimidation to be expected. Once a male betta fish gets close to another betta territory, they will puff their gills to seem bigger and spread their fins as a way of asserting dominance.

Sometimes, this intimidation tactic is enough to scare the other fish and avoid a fight. If it doesn’t work, then the fish will start nipping at each other. The fight can last a couple of seconds or even minutes. If there is enough room to retreat from the fight, then the fight might be over before it is begun. It can also end in a couple of injuries, but if both fish are very aggressive, it can end in death. They will usually circle around and bite at the fin and tail areas until one of the retreats or dies.

This is what happens in the wild. Tanks are a different story. Even though many have reported that inbred fish are much less aggressive, fights can still happen. Without much space or even places to hide, keeping two male bettas will most likely end in a death fight. It’s important to never keep two male betta fish without any form of barrier that will separate them both physically and visually.

You may also like to check out our article on how long do Betta fish live.

Blue betta fish

How to Avoid Fighting in Your Betta Tank

If you have some concerns about betta fish fighting in your tank, there is no need to be scared. You can take several actions to avoid fighting in your betta tank. Let’s take a look at the most important ones.

Choose the Right Number of Males and Females

Whether your bettas will fight each other or not will depend on the number of males and females you keep in your tank. Here are the usual combinations you might have in your tank and the precautions you need to take:

  • Two female bettas will coexist if there are enough hiding places in a large tank, but you will still need to keep a close eye on them.
  • Two males won’t be able to swim freely together, so you will need a partition between them so they don’t interact or see each other.
  • Males and females that are kept together will often mate, so avoid keeping them if you’re not ready for this.
  • Once the breeding is over, males will look after the eggs and they can chase off the female betta and kill other males that come close.
  • Having one male in the tank will reduce fighting, but there is still a possibility they might fight the females, especially after breeding.

Get a Large Betta Fish Tank

If you plan on having more than one Siamese fighting fish in your tank, you will need to get the largest tank you can. A betta fish tank of  25 gallons is the minimum size you need to consider. Betta fish will be less aggressive if you provide them with plenty of room to create their territory. Having more space in the tank will also keep any other fish from going to other territories once they have been established.

Make Sure to Create the Right Environment

When you’re setting up a tank and its environment, make sure you have the right water temperature and pH levels. Even the slightest change in conditions can stress them and cause them to be more aggressive than usual. And you should also include many hiding spaces with proper decoration.

Put Decorations and Hiding Spots

You also need to consider providing plenty of hiding spaces for your fish – both bettas and any other you might want to get. Having hiding spaces will let the fish feel more secure and even help reduce their stress levels. And it will also divide the tank, offer many areas for exploration, and keep them distracted. Not to mention that a hiding spot will end a fight before it’s begun by offering a place for retreat.

Place Other Fish in the Tank

Having other compatible fish in the tank can also help bettas avoid any fighting, especially if an order is established. But what are some compatible fish that can go with bettas? Among the many species, you should consider getting one of the following:

  • Zebra Snails – peaceful fish that is great for small tanks. They won’t breed quickly and eat algae and other debris
  • Feeder Guppies – suitable for tanks with a more peaceful betta. They are small and they will hide and avoid drawing attention to themselves.
  • White Cloud Minnows – a species that comes from the same native environment as bettas. They the same type of food and water, and bettas won’t see them as a possible threat.
  • Ember Tetras – submissive and peaceful fish that won’t attract any attention due to their bland and dull colors,
  • Harlequin Rasboras – they naturally exist with bettas in the wild, which makes them one of the best tankmates. They have the same habitat and diet, and the best part is that they have a non-aggressive nature.
  • Pygmy Cory – peaceful and small cory catfish species that like to live in groups of three or more, while staying out of the betta’s way.
  • Ghost Shrimp – pale and translucent fish that won’t draw much attention, but they will need plenty of places to hide.
  • Clown Pleco – submissive and gentle fish for large tanks with built-in protection
  • Short Fin Mollies – great peaceful fish that are easy to care for and perfect for any large tank. Their bright colors can get a betta’s attention but their size will discourage any fighting from happening.
  • Kuhli Loach – peaceful fish that are great for a tank of at least 20 gallons. They will stay at the bottom of the tank and make sure they’re not intruding on the betta’s territory.

Take Immediate Action

As soon as any fighting happens, you must take immediate action to stop it. If you hesitate, there might be some serious damage caused that ends up with death. When the fight starts happening, you will need to separate the fish entirely by placing them in different tanks or just dividing the current tank with partitions, ensuring that all areas of the tank are interesting enough to hold the attention of your fish.

White betta fish

Do Bettas Fight Other Fish?

Yes, bettas will fight other fish. If placed with other make fish, you can expect some fighting. They won’t fight every fish, but chances are that there might be some fighting due to the aggressive nature of bettas. Here are some of the main reasons bettas will fight other fish:

  • Small Tank
  • Not enough spaces to hide
  • The fish has similar characteristics as betta fish
  • Brightly colored fish may stress bettas
  • Long fins on a fish
  • The fish is aggressive

So, if you plan on having other fish in a tank, make sure you carefully choose with plenty of research and expert advice. You can also carefully look at bettas at the pet store to see which one is not flaring its fins or puffing its gills when it sees other bettas.

Final Thoughts

While males tend to be more aggressive, even females can still demonstrate their fighting spirit. But, even though betta fish are aggressive and extremely territorial, it’s not that difficult to maintain a betta fish tank. With proper preparation and research, you can create your betta tank and enjoy watching your fish swim freely and calmly.


  1. Why Do Betta Fish Fight? –
  2. Betta Fish Fighting – Everything You Want To Know! – Betta Care Fish Guide


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