Are Bettas Aggressive? (6 Signs Of Aggression)

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Last Updated on 2023-12-18

If you’re planning to own a Betta, you may want to know if the rumors are true: are bettas aggressive?

In this article, you will find out everything you need to know about the temperament that you can expect from betta fish, including when and why they might feel inclined to compete with other fish and what you can do to avoid having a fight on your hands.

Key Takeaways:

  • Bettas, both male and female, have aggressive tendencies, and whether they exhibit aggression towards other fish depends on factors like species, color, and territory.
  • Male bettas are more likely to be aggressive, especially towards other males, to establish dominance, defend territory, and impress females for breeding.
  • Female bettas can also display aggression, especially in groups, as they establish a hierarchy for resources like food and hiding places.
  • Bettas can live with non-aggressive tank mates such as snails, shrimps, and Cory catfish, but caution is advised, especially with fish that resemble bettas.
  • Signs of aggression in bettas include gill flaring, fin spreading, ramming, fin nipping, injuries, and changes in behavior.

Are Betta Fish Aggressive to Other Fish?

Whether or not your betta will be aggressive to other fish depends largely on the type of fish. While it does always come down to the temperament in your betta, some fish that have dull coloring such as corydoras and plecos, are mostly ignored.

However, Bettas do have an aggressive nature, and they will attack and even kill other fish in their tanks. In the wild, males often get physical with each other to claim and defend their territory, however, with the large amount of space they live in, they are easily able to run away from each other.

Of course, in a tank, this isn’t the case, and when fish can’t get away from each other the behavior will continue and even get worse.

Another reason why betta fish fight is to impress females and increase their chances of breeding. Males build bubble nests at the surface of the water that they use to attract females and ultimately protect any eggs that are lain.

So male bettas are likely to fight off any fish that they see as a threat to these nests to keep them looking impressive for potential mates.

And lastly, one of the most desirable qualities of the betta fish is their beautiful coloring and magnificent fins, but this flamboyant appearance is actually closely related to their aggression.

Like many other species, male betta fish attract females with their colorful appearance, and they will get into fights with other males, or other colorful fish, to assert their dominance and establish their position as the lead male.

Although aggression is much more common in male betta fish, females can also get physical with each other if they are in a group together.

Female bettas will generally have a hierarchy within their “sorority” that is dependent on who is the most dominant, and they will sometimes fight to establish their social standing.

Can Betta Fish Live with Other Fish?

In general, betta fish are most aggressive towards other betta’s, so you have to be very careful about how many you have in a single tank. Female betta’s are much less likely to fight one another, and a small group will normally become comfortable together in the same tank.

Male betta’s are known to attack one another just because they are in the same space, so first of all, never keep them together. Male bettas can also act aggressively towards females, so keep your male’s separate from any other bettas unless you are trying to breed them.

Betta’s, however, don’t have to live a solitary life, and they can live peacefully alongside non-aggressive fish from other species. Just make sure you avoid fish that have bright/flowing fins that make them seem too much like another betta.

Snails, shrimps, and Cory catfish are often safe tank mates for a betta.

However, most importantly, at the end of the day, every betta fish has its own individual personality, and some are much more aggressive than others. Before putting other fish in with a betta or adding a betta fish to a tank you already have, you will want to determine how aggressive they might be and try to reduce the risk of a fight breaking out.

(Here are 6 tips for how you can pick a friendly betta for your community tank!)

Are Female Bettas Aggressive To Other Fish?

Female bettas can be aggressive toward other fish but are generally less aggressive than male bettas. Female bettas can exhibit territorial behavior, especially towards other females, as they compete for resources, such as food and hiding places.

However, they are typically less aggressive towards other fish species than male bettas.

It’s important to note that the aggression level of female bettas can vary depending on their personalities and environment. Some female bettas may be more docile and peaceful, while others may be more aggressive and territorial.

Betta Bule Mustard Butterfly Halfmoon  HM Male or Plakat Fighting Fish Splendens  on Black Background.

Signs Of Aggression in Betta Fish

If you plan on putting betta fish into your tank, you need to be ready to spot the signs that they are starting to act aggressive. You might think that a fight is always going to be quite obvious to notice, but some of the signals that bettas give off are more subtle, and you aren’t going to have eyes on the tank at all times.

Gill Flaring

The first sign that your betta fish are becoming aggressive is when they try and make themselves look larger and more intimidating. If your bettas are flaring their gills, it is usually a signal that they are trying to intimidate other fish.

Spreading Their Fins

Along with flaring their gills, bettas will spread out their fins so that they appear to be bigger and stronger than a potential opponent. They are hoping to scare off the other fish and win the battle for dominance without having to get physical.


If the fight isn’t decided by their posturing and intimidation, then things will become physical and violent. One of the most common ways that bettas will try to hurt each other is by aggressively ramming their bodies together.

Fin Nipping

A particularly dangerous aggression tactic amongst betta fish is to nip at their opponent’s fins, trying to bite off chunks and cause harm. If these bites are bad enough, they can lead to fin rot and ultimately become fatal for the injured fish.


There are many major and minor injuries that betta fish will sustain through combat, and you might become aware of these before you actually witness any fights. If you notice chunks of fin missing, tears, dropped scales, or red marks on the bodies of your betta fish, they are probably fighting when you aren’t looking.

Changes in Behaviour

Another sign that bettas are getting aggressive with each other is sudden changes in their behavior. One might be acting more submissive and withdrawn, or another might be acting more intense and dominant.

What Triggers Betta Fish Aggression?

Aggression is usually triggered when betta fish are fighting to defend their territory from other bettas. More often than not, a male betta fish will be triggered when they feel threatened by another competing male, but that is not the only time that it will occur.

Stress from an unstable or unsuitable environment can also cause bettas to act aggressively.

Bettas can become physical and aggressive with other fish too, and it is generally believed that they do so because they either feel vulnerable or they feel the need to establish their own position.

Brighter colors and large, flowing fins trigger aggression from bettas because these characteristics are used to show dominance within their own species.

It is also believed that betta fish can become more aggressive during feeding times, particularly if they are feeling exposed, as they try to defend their meal and their right to eat.

If male bettas have built a bubble nest, they are also more likely to act aggressively to defend it and protect it from others.

Will A Betta Stop Being Aggressive?

Some betta fish are naturally much more aggressive than others, but there are very few that will always be aggressive all of the time. If you are aware of the specific triggers which are leading to your bettas becoming violent, it is possible that removing or reducing these can bring them back to a peaceful existence.

If your betta fish have just been introduced to a new tank, they may act a little more aggressively as they adjust. My old betta even used to flare at his reflection in the glass.

If the tank is safe, free from other aggressive fish, and meets all of their needs, though, they should calm down after a couple of weeks.

Once they have settled in, however, bettas that still act aggressively under certain conditions are doing so for a reason, and unless those conditions change then their behavior is likely to stay the same.

Bettas will rarely stop being aggressive of their own accord, so you will need to make some adjustments if you want them to happen.

Check out this video about Betta Aggression!

How Do Bettas Fight Each Other?

Bettas fish fight each other as a means of establishing dominance and territory. The process of betta fighting involves aggressive posturing and attacks, which can result in serious injuries or death for the fish involved.

When two male Betta fish are introduced to each other, they will often begin by flaring their gills and fins to appear larger and more intimidating to their opponent. They may also display a range of aggressive behaviors, such as circling, charging, or biting.

Once the fish have established their dominance, they will begin to attack each other with their sharp teeth and fins. They may nip at each other’s fins or bite each other’s bodies. The fight can last anywhere from a few seconds to several minutes, with one fish eventually retreating or being killed.

How To Make Betta Fish Less Aggressive

There are always things that you can do to help your betta fish feel more comfortable, less stressed, and ultimately less aggressive in their tank. The most important thing to consider is what may be triggering the aggressive behavior in the first place so that you can address it directly.

Keep Male Betta Fish Separate

Keeping your male betta fish away from other bettas is one of the most important ways to reduce aggression – most hobbyists won’t even keep males and females together unless they are actively breeding. Males should be visibly separated as well as physically removed because they can become aggressive even through a pane of glass.

Avoid Threatening Tank Mates

Some betta fish find it hard to live alongside any other animals at all, and even the more docile bettas can fight with the wrong tank mates. Brightly colored fish with flowing fins are often seen as a threat, and any fish species that are known to act aggressively should definitely be avoided.

Increase the Size of Your Aquarium

Having more room to move around can make a big difference for your bettas because they will be able to establish their own territory. It is still unlikely that two males will get along in the same tank, but they are more likely to be peaceful around other species in a larger tank.

Provide Additional Hiding Spaces

Another way to help your bettas to feel more secure and less threatened by their tank mates is to give them more places to hide. Vegetation and scenery can greatly reduce the amount of stress that your bettas are feeling and distract them from focusing on each other.

Ensure Stability

Betta fish need to be in a stable environment if you want to avoid stress and aggression. The levels of ammonia and nitrate in their water need to be carefully monitored, and the water itself should be kept at a consistent, safe pH level and temperature.

Are Wild Bettas Aggressive?

Wild bettas can display aggressive behavior. However, the degree and frequency of aggression can vary depending on the species and the individual fish.

Aggression in Wild Bettas

In the wild, bettas live in small bodies of water such as rice paddies, swamps, and slow-moving streams, where competition for resources and mates is high. This environment has made them evolutionarily adapted to be territorial and aggressive. Male bettas are especially territorial and will defend their area aggressively against other males.

Betta aggression is typically displayed through flaring their gills and fins, charging, and biting. In the wild, bettas may display aggression towards other fish species or even their own kind, particularly during breeding season or when resources are scarce.

Variation in Aggression

While wild bettas can be aggressive, the degree of aggression can vary depending on the species and the individual fish. For example, some species of wild bettas, such as the peaceful betta (Betta Imbellis), are less aggressive. Additionally, individual fish may have different temperaments, with some being more aggressive than others.

Are Bettas Aggressive_ (6 Signs Of Aggression)


If you want to know more about aggression in bettas, then here are the most frequently asked questions that people have!

Which Betta Fish Is the Most Aggressive?

Of all the different varieties of betta fish out there, Plakat Bettas are considered to be the most aggressive. They were actually bred in Southeast Asia specifically for the sole purpose of fighting.

Are Bettas Aggressive To Other Fish?

Betta fish can be aggressive towards other fish, particularly those with long and flowing fins, bright colors, or similar body shape to their own.

However, the degree of aggression can vary depending on the individual betta fish, their environment, and the other fish species in the tank. 

Will Betta Fish Fight To Death?

Betta fish can and do fight each other to death, especially if they are not given sufficient space and resources or are introduced to each other in a hostile environment.

However, these fights normally happen over time, and in most cases the bettas will succumb to the amount of injuries they have.

Are Male Betta Fish Aggressive To Females?

Male betta fish will be aggressive towards females, momentarily lapsing during the breeding process. However, outside of breeding situations, you should always remove your female bettas from a males tank.

Do Male And Female Bettas Fight Each Other?

You should avoid keeping male and female bettas together as the chances are they will end up fighting each other still. It’s best to either keep a sorority of females, or males on their own.

Are Koi Bettas Aggressive?

Koi bettas have naturally aggressive tendencies, like all bettas. However, the degree of aggression can vary depending on the individual betta and their environment.

Koi bettas have unique color patterns that may make them more attractive to other fish, increasing the risk of aggression toward them. 

Are King Bettas More Aggressive?

There is no evidence to suggest that king bettas are more aggressive than other types of betta fish. Like all bettas, king bettas have the potential to be aggressive toward other fish.

Still, the degree of aggression can vary depending on the individual fish and their environment.

Are Betta Fish Aggressive Towards Humans?

Betta fish aren’t typically aggressive toward humans. In fact, many betta owners find them to be quite friendly and interactive.

However, betta fish may exhibit defensive or territorial behavior like any animal if they feel threatened or are mishandled. 

Even with all this in mind, there is no way your betta could harm you.

Are Halfmoon Bettas Aggressive?

Halfmoon bettas have the same natural aggressive tendencies as other betta fish. These bettas have large, flowing fins that may make them more vulnerable to attack from other fish, and they may exhibit aggression towards other fish with similar body shape or long fins.

Are Crowntail Bettas More Aggressive?

Compared to other types of betta fish, crowntail bettas are not necessarily more aggressive. However, like all bettas, they can be territorial and aggressive towards other fish and even other bettas, especially during breeding.

Are Female Koi Bettas Aggressive?

Yes, like all bettas, female Koi Bettas can be territorial and aggressive towards other fish, including other bettas. However, they are generally less aggressive than males and can usually be kept together in groups under appropriate tank conditions.

Are Veiltail Bettas Aggressive?

Like all bettas, Veiltail Bettas can be territorial and aggressive towards other fish, including other bettas. However, their aggression level can depend on various factors. 

Are Female Elephant Ear Bettas Aggressive?

Yes, but their level of aggression varies from individual to individual. While they are generally less aggressive than male Bettas, they may still display territorial behavior toward other fish in the tank, especially if the tank is too small or lacks hiding places.

Are Dragon Scale Bettas Aggressive?

Yes, Dragon Scale Bettas can be aggressive towards other fish, especially if they feel their territory is being invaded or if they are stressed. However, the level of aggression can vary from individual fish, and some Dragon Scale Bettas may be more docile than others.

Are Female Bettas Aggressive To Guppies?

Female bettas can be aggressive to guppies, especially if they’re getting harassed too much. Male guppies can incite aggression because of their tails, and also because they may try to mate with the females.

If you planned on keeping female bettas and guppies together the best chance of making it work is to keep female bettas with female guppies.

However, even then, they may still end up being aggressive.

Are Betta Fish Aggressive To Goldfish?

Due to the large size of goldfish, it’s unlikely a betta would be overly aggressive. However, depending on the type and size of goldfish, aggression is entirely possible.

Regardless of this, goldfish and betta can’t be kept together due to differing tank requirements anyway.

Recap: Are Bettas Aggressive?

So, are betta fish aggressive? The answer is yes. They didn’t gain the name “Siamese fighting fish” for nothing. Bettas are well known for fighting amongst themselves and with other fish species, sometimes causing serious injuries and even death.

Female bettas can often live together in small groups, but male bettas usually need to be kept completely separate from other betta fish. If their conditions are stable and their needs are met, most betta fish can live alongside non-aggressive fish species but some have a tendency to fight anything in their tanks.


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