Why do betta fish get angry?

In this blog we will discuss the common reasons why betta fish get angry and how to calm them.This blog will help betta keepers how to deal with their angry bettas.


In this blog

  • Why do betta fish get angry?
  • Signs of angry betta fish
  • How do you calm an angry betta fish?
  • Summary 
  • Frequently asked questions
  • Reference 

Why do betta fish get angry?

Betta fish get angry when something in their territory threatens them and they want to get rid of it as soon as possible.It could be another betta, a tank companion, or a reflection of them.

If the betta territory is threatened

  • A fighting fish will exhibit more aggressive behavior when more valuable resources are threatened by competing male fish.
  • It’s a way to make themselves look bigger to protect their territory.
  • Male betta fish erupt violently when their territory is invaded or threatened by another tank mate.
  • Territorial behavior varies by gender, but both male and female betta fish can be aggressive against other fish as well as the same species.

If bettas are kept in cramped tanks

With tanks less than 5 gallons, bettas cannot extend their lifespan. In an aquarium, a betta needs to live for 3-5 years. 

With a cramped 2.5-gallon tank, bettas can’t live that long. If the tank is too small, they may die prematurely due to anger and stress.

Bettas don’t like small spaces where they may become more angry and aggressive.

Overcrowded bettas tank

If betta tanks are overcrowded, they may show signs of stress, anger, aggression, toxicity, and lack of oxygen. 

Overcrowding can cause a stress response, stunt growth, lower immunity, and make betta fish susceptible to illness.

Non-compatible betta tank companion

One should never keep these tank mates in bettas tank,as they trigger anger and aggressive behavior in bettas:

  • Other bettas. 
  • Ghost shrimp.
  • Gourami.
  • Goldfish.
  • Cichlids.
  • African dwarf frogs.
  • Schooling fish. 

Bettas seeing their own reflection in the mirror

The betta is a very territorial fish, so if it sees its reflection, it will try to scare it from its territory.

If you think your betta is seeing his own reflection,then he will not only walk up and down the side of the aquarium, but it will also flare out of anger.

Bettas not fed on time

If they don’t eat the food they need, the bettas will be frustrated and more aggressive, but this depends on the individual bettas. They need a high-protein diet.

Otherwise, they will run out of energy and their health will be poor. This is enough to make the betta fish a little moody and angry too.

  • Betta can harass or attack other tank companions if they are hungry and not fed on time.
  • If they don’t eat on time, they can get frustrated and angry.
  • A hungry betta fish will let you know that it is not satisfied.
  • If they don’t eat the food they need, they will be frustrated and more aggressive.

Other male betta in bettas tank

Bettas show anger by flaring up to appear bigger than they really are. This behavior also prevents a full blown fight where one fish could get hurt, as one fish will usually retreat and move to another area before anything becomes physical. 

This is why you should never put two male bettas in an enclosed space in an aquarium, as there is no escape route and they may end up fighting to the death.

Another betta tank adjacent to betta fish tank

If you have a separate tank with many bettas in it, it is important to block their view of the adjacent tank. In order to be aggressive and angry, all a betta needs is another betta.

If you need to accommodate 2 bettas in the same aquarium, you must ensure that they both have enough space to escape a potentially dangerous situation and there must be adequate hiding spots.

Water temperature too high in bettas tank

Water that is warmer than their normal temperature will increase their activity and your betta will be angrier than usual.Hot water increases the metabolism of betta fish, which can make them uncomfortable and quickly age.

Ammonia pollution in bettas tank

Due to the closed environment, bettas aquariums are susceptible to the accumulation of unwanted ammonia. This is due to improper filtration of fish excrement and remaining food molecules. 

Such high concentrations of ammonia in the water burn the gills of the fish, which causes respiratory distress and anger issues in betta fish.

If bettas are bored

If you put your betta in a small unadorned tank and feed it the same food every day in the same environment, it will get bored very quickly. And this boredom often leads to anger, depression and stress.

If bettas are sick and left untreated

Bettas that feel sick either become very lethargic or show signs of depression through outbursts and other signs of aggression.

  • A sick betta can be annoying, angry, and stressful.
  • If your betta is sick, his level of activity will drop.
  • Bettas will hide in the bottom of the aquarium more often than usual.

Signs of angry betta fish

Bettas open their gill covers and usually extend their fins as well. It might be because they are angry, but they look very pretty when they do it.

  • Gill flaring-Flare is a term used to describe how a betta puffs up its gills, making it look much larger.
  • Ramming or fin nipping- Bettas attack other tank mates by nipping their fins, when they are angry.
  • Actively fighting-Bettas actively fight when they are angry either with other male bettas or non-compatible tank companions.This could be due to resources, space or for mating purposes.
  • Missing scales- Angry bettas will have missing scales.
  • Torn fins-Angry bettas will have torn fins due to fighting with other male bettas or non-compatible tank companions.
  • Increased hiding- Bettas tend to hide more when they are angry.
  • Swim erratically-Bettas tend to swim erratically or in abnormal manners when they are angry.

How do you calm an angry betta fish?

Hiding spots allow bettas to relax. This gives them places where they can rest without fear of being attacked, and also allows them to feel safe if they get stressed out with anger. Some good hiding places are live or fake plants,coconut caves, as well as various decorations.

Adding compatible tank companions can also calm your angry bettas.It is very important to choose their tank mates wisely.

Maintain water temperature in bettas tank

Betta fish need a steady and consistently warm water temperature – preferably between 75-85 degrees Fahrenheit.

It is best to keep the betta fish aquarium out of direct sunlight as this will cause temperature fluctuations as the temperature of the water needs to be stabilized.

Live plants for bettas

Live plants acts as good hiding spots and help to calm your angry bettas:

  • Water sprite
  • Betta bulb
  • Sword plant
  • Java fern
  • Vallisneria
  • Anubias 
  • Marimo moss ball
  • Cryptocoryne

Fake plants for bettas

Fake plants acts as good hiding spots and help to calm your angry bettas:

  • Qumy artificial aquarium plants. 
  • Maxfox fish tank plants floating hammock bed. 
  • Blue spotted betta plant red anubias leaf.

Caves for bettas

Caves acts as good hiding spots and help to calm your angry bettas:

  • Floating log den.
  • Mopani wood aquarium decor.
  • Marina decor polyresin cave.
  • Spongebob’s pineapple house.
  • Natural coconut cave. 
  • Sinking ceramic betta log.

Decorations for bettas

Decorations acts as good hiding spots and help to calm your angry bettas:

  • Shipwrecks
  • Leaves
  • Foliage 
  • Balls
  • Driftwood
  • Rock formation

Toys for betta fish

Betta fish enjoy mental stimulation and there are many betta toys on the market to deal with the problem of boredom.

Betta likes to explore and interact with toys around them. Bettas can be taught tricks with toys like ping pong balls and hoops, or with a fish training kit.

Compatible tank companions for betta fish

  • Zebra snails 
  • Marimo moss balls 
  • Feeder guppies 
  • Cory catfish 
  • Kuhli loach 
  • Neon tetras
  • Bristlenose

Treating ammonia poisoning in bettas tank

  • Add ammonia removal media to the filter.
  • Limit the food given to the betta.
  • Add an ammonia detoxifier. 
  • Add nitrifying bacteria in bettas tank
  • Change water frequently in bettas tank
  • Filter the water in bettas tank
  • Buy a tank large enough for bettas
  • Clean the bettas tank frequently.


Betta fish get angry if there is not enough space to swim,if the territory is threatened, or if they are not fed on time.

Avoid keeping bettas in small and overcrowded tanks.Keeping them in small spaces is not good for their overall health.It is very important to select a right sized tank for bettas.

Avoid putting two male bettas in the same aquarium as they will quickly become aggressive, angry and fight to the death. For a while they may remain peaceful, but sooner or later they will fight until only one remains.

An angry betta flare is enough to display how they feel by flaring the gills,spreading the fins, and showing the feeling of swimming irregularly around the aquarium.

Help your angry betta fish with toys, plants, & other aquarium-friendly items. Bettas loves to lie on the leaves, hide behind the logs and play with the balls.

Maintain water temperatures in bettas tank, using a suitable heater and thermometer.Make sure the aquarium water is not extremely hot or cold, as it can affect their metabolism.

The best way to prevent bettas from getting angry is to feed them at least once or twice a day, and feed them an amount that can be finished in about 20-30 seconds with each feed until they are satisfied.

Avoid feeding expired food to your bettas. Always check the labels before feeding them. Don’t compromise with the quality of food at any cost.

Betta is popular for its tantrums, which you will definitely know when you pick up an angry betta fish.

Frequently asked questions