Male betta fish, like the betta splenden, blow bubbles and build bubble clusters (nests) for reproduction. It’s the first step in the mating process with nest building starting as soon as they are old enough to reproduce.
The bubbles act as a safe haven for the eggs during incubation and for the fry until they are old enough to swim and get oxygen from the surface on their own. Bubble nests, which are also commonly referred to as foam nests, are created by gulping air and blowing oral secretion (saliva) bubbles, near the surface of the water.
In your tank, you can identify a bubble nest as the collection of bubbles on the surface of the water. The male will instinctively build a bubble nest with or without a female present. This is why you may find a bubble nest in your tank even if your betta has never seen or had contact with a female.
Bubble Nests and Mating In The Wild
In the wild, a male betta fish must fight for his territory against others. Once his territory is established, his nest is typically built under leaves or other types of debris. If a female is present for mating, and she deems the nest suitable, the male will coax her under the nest until she submits.
After the male’s embrace and the spawning have occurred, it’s the male’s job to collect the eggs with his mouth, and then place them in the bubble nest. There he guards the eggs, ensuring they do not fall out of the nest. He protects them from potential predators until they are old enough to survive on their own. Mating in captivity is, however, only recommended for experienced hobbyists.
Betta Bubble Nest Building Frequency
All betta fish are unique, and therefore the frequency of their nest building will also be unique. Some bettas may build one on a regular basis, while others might be more infrequent or not at all. Daily, weekly, or monthly are all common time-frames for male bettas to construct a nest.
Some nests are large, some are small, and their thickness can also vary. Regular bubble nest construction can be a sign that your betta fish is happy and healthy, and would be suitable for mating. It’s also an indication that your betta feels safe and has established his tank as his territory. Adequate plants and places to hide will help to create a less-stressful and safe environment.
What If A Male Betta Is Not Making A Bubble Nest?
If you have never seen your betta fish build a bubble nest, don’t panic! There is no real necessity for him to build a nest unless you plan on breeding. A lack of nest building behavior does not necessarily mean your betta is unhappy or unhealthy.
Reasons Why A Betta May Not Make A Bubble Nest –
- Current age and level of health
- Strong filtration units causing strong water current
- Poor water quality and cleanliness
- Water temperature is too cold (ideal is 78-82 degrees Fahrenheit)
- Lack of plants, decor, or surface debris
Properly caring for a betta fish does go a long way in providing the right environment and conditions for nest building.
Bubble Nest Motivation (how to encourage making one)
Different stimuli have been associated with nest building behavior. These may include changes in temperature, fluctuations in rainfall, barometric changes, tank materials, and the presence of females, or even other males.
Whether you’re interested in breeding your betta or just curious what a bubble nest looks like in person, there are ways to help encourage your betta to construct one.
Some Helpful Tips Include –
- Keep the water and tank clean
- Maintain tropical temperatures (78-82 degrees Fahrenheit)
- Introduce floating plants like Indian Almond Leaves or Amazon Frogbit
- Only use gentle flow filters. Strong currents deter nest building
- The presence of a female betta will encourage nest building. A female can be floated in a cup in the male’s tank or on the other side of a divider. Extended periods of visibility are discouraged because it can create a lot of stress.
DIY Floating Debris
While live plants found in their natural habitat, like the Indian Almond Leaf, are best, you can also use regularly found household items if you’re on a budget. Floating debris encourages a male betta to build his nest under it because of the protection it provides.
Take a styrofoam cup and cut it in half lengthwise. Then lay it on the surface of the water. Check back periodically for any signs of a nest being constructed beneath it.
Plastic lids from food containers also work well. The lid from a Pringles Chip can, for example, is a decent size and easy to add to the surface of the water. Make sure any item you introduce has been cleaned with hot water (no soap) first.
How To Clean Your Tank Without Ruining A Betta’s Nest
What if you find this wonderful work of art called a bubble nest and it’s time for a cleaning? First, you’re filled with excitement. Next comes anxiety about what to do with the nest and how to clean your tank without ruining the bubble nest your betta worked so hard to create.
It’s perfectly fine to destroy the nest for cleaning purposes as long as it doesn’t contain eggs. It’s more of a priority to have a clean tank than it is to salvage the nest. In fact, your betta will be less interested in making bubble nests again if the water is dirty. Worse yet, he could get sick.
If you’re feeling really guilty about keeping the nest intact, you can scoop up the nest with a plastic cup. Once you’re done cleaning the tank, gently place the nest back on the surface of the water.
If you have any further questions about why, how, when, or just want to share your own betta fish bubble nest stories, leave a comment below.
Lots of information, thank you!
Now I’m the guiltiest betta-mommy. My blue veiltail is my first baby, had him a week ago. Three days ago I found a lot of bubbles floating underneath the big leaf and the moment I saw I scooped it out twice thinking it would harm my new baby! Bad mommy! (I didn’t know then what it was!)
This is a great article! I don’t currently own any betta fish but it’s so interesting to learn about them. Thanks for sharing.
My beta also is bubbling. I’m getting ready to change of water so goodbye to the bubbles will have to start over. The article was really helpful, I had no idea what the bubbles were and now I know.
Stanley. Ok to discard bubbles when cleaning tank. Henry (my Betta) came right back and built another nest…I.e. more bubbles.
Glad to know he’s happy!! 😀
I put a female betta in a community tank with a resplendent male (blue), and he started a bubble nest. How will I know if they will mate??
Breeding can be tricky, and I would only attempt it in another tank away from other tank mates. If the both of them think each other are suitable mates, then they will likely choose to mate. If not, there’s not much you can do if there’s no interest between each other with that pair. The male appears healthy if he built a bubble nest in her presence though.
She will inspect the nest and if it is up to her standards, she’ll then playfully swim with him. She will swim away too and will put her head down as submission. When they release the eggs, he will squeeze them out of her by wrapping around her middle. Then she will be very lethargic after that. You take her out after that, but sometimes you don’t notice when the “embrace” happens, so you have to watch the behaviors carefully. He’ll start collecting the eggs in his mouth and place them in the nest. You’ll see little white dots in the bubbles. Do not feed him during this time! He can go over a week without eating, so he needs to focus on watching the eggs and keeping them in the nest. It is also important that when you take out the female to keep her in a separate tank for a day or two with almond leaves and some anti fungal treatment to treat her ripped fins or any other cut she might have. The mating process can be and most of the time is rough. You can feed her once she’s away from the eggs and the male. Back to the nest.. watch the eggs and after a day, you’ll start seeing tiny, almost microscopic tails hanging from the bubbles. Get a magnifying glass to make it easier. The next day, you’ll start seeing little eyes at the top of their heads. Still keep the daddy with them as he makes sure they aren’t falling out. Once they are free-swimming, you can take him out. The fry won’t swim horizontally yet due to their swim bladder not being fully developed. During this time do not feed them. Their sacs provided them with nutrition and the microorganisms in the tank that are invisible to us are what they eat after that. Once they swim horizontal, you begin to feed them hatched baby brine shrimp, vinegar eels, paramisium and even hard boiled egg yolk. Anything left over, at the bottom of the tank, you need to take it out. They will continue to grow. Note: not every fry will make it. After a couple months, you will need to separate them because even though the grew up together, they will become territorial, especially the males.. have a plan with what you’ll do with all the new bettas
Good luck
I have two bettas in one tank they do not fight but keep making bubbles they just pass by each other doesn’t even flare so is one of them is male or female? I can see the egg tube on one but I didn’t observe that on another one
I just got my new Betta yesterday and he’s already making a bubble nest is that a good thing?
Yeah that’s a good thing – means he feels safe in his habitat and healthy.
Oh that’s good, thank you
I got mine five days ago and he has started in the last day making bubble nests..and not just one. At this rate he will fill the top of the tank in few days.. Is this normal lol?
Some build much larger nests than others. It’s normal, nothing to worry about! You will likely see him get very aggressive if you approach the tank near his nests which is a fun sight to see.
about a month ago I got two betta fish. A few days after I noticed a few major differences in how they acted one was swimming around curious and the other only stared at the wall and looked sad. I got worried when the sad one stopped eating so I did some researching and he didn’t seem to be sick. About a week later he died. My surviving fish has made a bubble nest on the top of his tank. Everywhere I read that this is a sign of a happy healthy fish but my fish is acting just like the one that died earlier! Am I right to be a bit worried about this change in his attitude or am I just over thinking it. If making a bubble nest is such a good sign why is he acting like this is there a reason?
Sorry to hear about your other betta. You may be overthinking it, or it may be something regarding his care. Bubble nest building is a sign of health and ability to mate, so it’s a good sign of overall health. Not all bettas will make them frequently though. A lethargic or lazy betta that looks sad is usually from water that is too cold. Is your tanks water temperature within the proper range of 76-82 degrees? If not, please get a heater.
Well he only acts like this when he has made a bubble nest. He floats at the top next to them for minutes on end then he swims around the tank once the and goes right back to the bubbles. When I clean the tank and all the bubbles he goes right back to the happy go lucky fish he is. But I might just be over thinking this. You can just tell me I am crazy and my fish is is just fine. If you don’t think anything I have seed is concerning
If it’s during the bubble nest building it’s likely his behavioral instinct to stay close to the nest and be territorial over it – waiting to impress a potential mate. This is evident since you said he doesn’t act this way when the nest is gone. Nothing to worry about just instinctual behavior.
I’m a new betta fish owner and I’m concerned about the bubbles in my tank. I do want anything to happen to Bob the Betta.
If it occurred after adding new water to the tank, that’s normal it’s just oxygen bubbles and they will go away over time. If the bubbles are on the surface, it may be a bubble nest being built by the betta.
I inherited this Betta fish 2wks ago. after transport, changing the water, he seemed very happy. He would respond swimming happily whenever I came close and fingerplayed around the outside of the aquarium. He came up t meet the food I dropped on top of the water. The water was getting murky and surprise, yesterday I woke to a bubble nest. I panicked thinking it was a bad thing and changed the water. He now seems sad. staying at the bottom not respond to me at all. He’s not eating either. It’s been 4hrs. I warmed the water but? What should I do? He’s hiding in the rocks motionless. Will he recover?
If you changed the water and it was an abrupt change (different temperature/parameters) it could have stressed your betta. He should recover.
HELP!!! Going out of town for2-3 days for 1st time w/o Hank. I can’t find the proper auto feeder and I won’t give him a “vacation” block feeder. Is a surface feeder better than no food? What Kind? Running out of time.
P.S. I think he knows ,JK
I don’t recommend vacation block feeders. Please view the vacation guide here.