Betta Fish Flare – What You Need To Know!

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Betta fish can demonstrate an exciting behavior called flaring, which is the sudden expansion of their gill covers and opening of their mouths.

Betta fish flare can sometimes look aggressive towards other fish, but this is often not the case.

A variety of stimuli can trigger Betta flares, and Betta owners that know the warning signs of flaring might be able to prevent their betta fish from getting into a dangerous situation or stressed.

In this article, we’ll explain why your Betta is flaring, if it’s good or bad, and the steps you can take to stop your Betta from getting triggered!

Why Is Your Betta Fish Flaring?

Flaring is a sign that your Betta feels threatened either by another Betta, an aggressive fish species, or their environment.

A few of the main reasons a Betta will flare are:

Defending Territory

Betta fish have various methods to help them defend their territory.

For example, the Betta fish will flare to intimidate an aggressor into leaving. Betta fish will also flare when they are showing dominance over another Betta or other fish in the tank.

During Breeding

Betta fish begin to flare at each other when they are breeding. Male Betta’s will flare their fins and gills as a way to show dominance over the female, who has been following them around.

Protecting Eggs

The male Betta will also flare when he is guarding his eggs, which signals the female not to come close to her eggs or fry.

Betta flares can also be triggered for the following reasons:

  • Threatening gestures from other Betta’s (i.e., fins up)
  • Aggressive behaviors from other fish (darting, chasing, etc.) Here is a list of fish that can live with Bettas.
  • A small aquarium that makes your Betta feel trapped or crowded
  • Stretching or boredom
  • Angry or happy
  • After a water change
  • New home

Why Your Betta Flares At You?

Your Betta’s most likely reason for flaring at you is that they view you as a potential threat. Betta fish flare when they’re feeling threatened, and their natural reaction to seeing something coming towards them is to puff up, flare out their gills, and extend the spines along their backs.

A few other reasons are:

New Tank?

Your Betta fish is most likely flaring when you first set up your tank because they sense the new environment. This initial startle period can last anywhere from a few hours to a couple of weeks before they become comfortable in their surroundings and begin exploring what’s going on around them.

Threatened When They See You Coming

Your Betta fish flares when they see you coming in their direction because they perceive this as a threat toward them, so they puff up to appear bigger and more intimidating.

Betta’s, especially younger bettas who are still establishing themselves in the tank, will also flare when they have just woken up from a nap or are threatened by another fish.

Why Bettas Flare At Reflections?

Betta fish flare at reflections to make themselves appear larger. Betta fish are not intentionally trying to scare off another fish or their reflection; instead, they are attempting to intimidate other Betta fish into thinking that they are bigger than them so that the other Betta will back down.

When Betta’s see another Betta looking at them, they flare to appear bigger. Betta’s are very territorial, so it is common for Betta fish to flare at each other when in the same tank together.

Because a reflection appears to be another Betta in the tank, this can be stressful for your fish and you should try to reduce as many reflections as possible.

How To Reduce Reflections In Your Bettas Tank

Possible steps to reduce reflections in a fish tank:

  1. Use decorative plants or stones to give the illusion of two walls since Betta’s are less likely to flare at their reflection if they are looking at something. In addition, they tend not to flare when there is nothing for them to defend.
  2. Avoid bright lights in the room to reduce the chances of your Betta seeing their reflection. Fluorescent lighting is especially strong and can reduce a Betta’s willingness to flare at “the other fish.”
  3. If possible, move the tank away from visible windows or doors that cause reflections from light sources. The more neutral space the better.
  4. Cover up or paint the sides of your aquarium.

Video: Floating Betta Mirror | Flaring Bettas

Is Flaring Bad For Your Betta?

Flaring is not necessarily bad, but it can be dangerous for your Betta fish.

If you think of flaring as a warning sign that your Betta is feeling threatened or uncomfortable, then you should take action to reduce the stress level in your Betta’s environment.

What Should You Do?

Although occasionally Betta fish will flare, especially after waking up, it’s essential to be aware of the frequency with which your Betta is flaring and how he flares.

If you notice that your Betta is constantly aggressive or wants to fight with other fish in the tank, it’s best to either get rid of the tankmates or put your Betta in a different environment.

You can also find ways to reduce stress.

Ways To Reduce Stress For Your Betta

Reducing stress for your betta fish is a great way to reduce flares. If you reduce the potential threat in your Betta’s environment, they will be less likely to flare at their reflection or other fish.

Some ways that you can reduce stress in your Betta fish tank include:

  • Using live plants, real or fake, instead of plastic decorations.
  • Using a big tank
  • Feeding healthy diet to avoid a bloated Betta.
  • Water quality

How To Stop Flaring Behaviors?

If you have noticed that your Betta is flaring, there are a few things you can do to help prevent this behavior from continuing.

Start by keeping your Betta fish away from other fish until you are sure they will get along. If you have had issues with the other fish being aggressive to your Betta, there have likely been some injuries inflicted, resulting in your Betta’s fear of the others.

Is Flaring Good For Your Betta?

Flaring is not always bad for your Betta. It is part of their natural behavior and sometimes a sign of playfulness or breeding.

But it can be dangerous.

If you reduce the stress in your Betta’s environment, they will be less likely to flare due to stress.

Do Female Betta Fish Flare?

Yes, female betta fish do flare. However, this is a natural behavior for male and female Betta fish.

Females will flare when she is protecting their babies or territory. Flaring can also happen when a female sees another Betta fish looking at her.

Did you know it’s okay to keep more than one female Betta fish together in one tank!

In A Sorority

If kept in a sorority tank, chances are you’ll see your female Betta flare quite often, and they play with and try to defend territory from other females.

However, the good news is that females are far less aggressive, and if you reduce stress factors, chances are the flaring is just part of their natural behavior.


If you’ve ever seen a Betta fish flare, it could be for fun or because they are stressed.

Flaring is often done for different reasons but usually occurs as an act of aggression between two male Bettas during mating season or if there are too many other fish in the tank with them.

The good news is that most flares are harmless!

But, sometimes, these aggressive acts will lead to injury, so it’s best not to keep more than one male Betta together.

For more information check out our Betta Care Guide!

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