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How and When Do Betta Fish Sleep?

Eric is an aquarium enthusiast with over two decades of experience caring for a wide array of tropical fish.

How do betta fish sleep?

How do betta fish sleep?

Do Betta Fish Sleep?

Yes! Like most animals, betta fish require sleep to be healthy. Bettas may sleep while lying on the bottom of the tank, or while floating at the water surface. They may rest on a plant leaf, or they might find some other area of the tank where they can doze off.

However, betta sleep is different from what we humans experience. When fish sleep they are still alert to danger and able to react to threats fairly quickly. It is more like a light resting state, compared to the deep sleep experienced by land mammals.1

Some betta keepers notice their bettas resting all the time and become worried. Others don’t see their fish napping at all. It is important to realize individual bettas may behave very differently. Some rest during the day, some may only rest at night, and some do both.

So, don’t become concerned if you notice your betta fish lying on the bottom of the tank now and then. If he appears otherwise healthy, he was probably just napping.

Likewise, try not to worry if it seems like your betta is always active. He will rest when he needs it, probably at night while you too are sleeping. You might be able to catch him snoozing if you peek into the tank when the light is off.

This is one of the reasons it is a good idea to have a light for your betta tank. As it does in humans, a day/night cycle gives your fish a chance to get some rest.

How Can You Tell If a Betta Fish Is Sleeping?

Betta fish don’t have eyelids, and the never enter deep REM sleep.2 So how do you know when they are snoozing?

Truthfully, it can be tough to tell for sure. However, there a few indications that may tip you off to a slumbering betta.

Bettas may sleep while:

  • Lying on the gravel.
  • Hiding inside a decoration.
  • Lying on a plant leaf.
  • Tucked between two decorations.
  • Floating at the surface.
  • Lying on their side.

I have gotten panicked questions from new betta owners about each of these situations, but in most cases, the betta is just taking a nap. Unless you notice other signs of disease or distress, it is best just to let him rest.

While bettas might snooze in many different places, you want to set up your tank so that they can rest when they need it. If the current is too strong, and he has nowhere to go, your betta may end up resting in a corner of the tank or even tucked behind a decoration.

Instead of letting that happen, make sure there are hiding spots and plenty of plants (real or artificial) where your betta can rest when he needs it. If plants aren't possible because you have a small tank or bowl, I suggest trying a betta hammock. They look like plant leaves and they are made especially to accommodate napping bettas.

If your betta appears to be sleeping, just let him rest. Disturbing him may cause stress, and stress is one of the biggest reasons betta fish die too soon. Unless he is exhibiting other problems, it is best to leave him be.

Some bettas may rest on plant leaves.

Some bettas may rest on plant leaves.

Is Your Betta Sleeping or Dead?

Bettas reduce their respiration while sleeping. This means your fish may look dead while he just catching a nap. How do you know when your betta is just resting, or when it is time to panic?

Certainly, bettas can pass on unexpectedly, but there are some signs to watch for which can tell you if your betta is ill, and if his next nap may be his last. These include but are not limited to:

  • Swimming sideways or upside down. This is an indication of swim bladder issues.
  • Bloated sides resulting in a pinecone-like appearance of the scales. This is a sign of a disease called dropsy.
  • Tiny white specs all over the body. This is a protozoan parasite infection called ich.
  • Black spots on fins along with degradation of the fin itself. This is fin rot.

You can greatly reduce or even eliminate the chance of your betta encountering these issues by following good tank management practices. This includes testing your water frequently, performing regular water changes, and making sure it is the right temperature for tropical fish. When you know your tank is healthy you can be more assured that your betta is healthy, and that when he is lying on his side he is only taking a rest.

While I advise you to let your betta sleep in most cases if he remains in one spot for a very long time and you become concerned you may try to net him or lightly touch him with the net. Like all fish, bettas are light sleepers, and he should react if he is healthy.

Betta Sleep FAQ

Here are a few more questions related to betta fish sleep and behaviors:

Why is my betta lying on the gravel?

As you now know, this is totally normal behavior and there is a good chance he is just resting. However, be on the lookout for signs that something might be wrong. Watch for signs of illness such as those described above and treat accordingly.

Do betta fish sleep with the light on?

Your betta will sleep with the light on and may nap during the day when the light is on. However, to make sure he gets the rest he needs you’ll want to turn his light off at night. For tanks without live plants, there is no need to have the light on more than 8-10 hours per day.

Are betta fish lazy?

Some of them seem to be! If you have had more than one betta fish you may notice a difference in their behaviors. One may be super active, constantly swimming around the tank and exploring everything. The other may be more lethargic, moving more slowly and resting more often. This doesn’t necessarily mean anything is wrong. It simply means different fish behave differently.

How many hours do betta fish sleep?

Again, this depends on the individual fish. You may notice your betta taking short naps during the day, and sleeping for longer periods at night. Like people, some bettas need more rest and some less. If you make sure you are providing that day/light cycle where you have a period of time when his light is off your betta should have plenty of opportunities to get the rest he needs.

Are betta fish nocturnal?

Not according to the strict definition of the word. Nocturnal animals rest during the day and are active at night. While it may seem like your betta is doing this, that’s not how bettas behave in the wild. If he is hiding a lot during the day it may because there is too much activity around the tank. He may be active at times when you are not around.

Do betta fish sleep upside down?

While it is more common for bettas to sleep on their bellies or on their sides, they may occasionally rest upside down. This can be extremely disconcerting for the fishkeeper, but treat it as you would any other time he appears to be resting.

Are betta fish sensitive to light?

The lights that come with aquariums should be fine for tropical fish, including bettas. However, shining a light directly at your betta may startle him, and doing it too often can cause undue stress. You also want to be sure not to set up his tank in direct sunlight. This may warm the water too much, and it can result in excess algae growth. It may also disrupt his sleep patterns, depending on how strong it is.

Learn More About Betta Fish

Keeping your betta happy and healthy means learning as much as you can about this beautiful fish. Take some time to read this betta fish care guide which answers many of the questions new betta owners face.

If you can maintain your aquarium and care for your betta fish properly it is one more worry off your mind when you see him lying on the gravel. There is a good chance he is just sleeping, and you can just let him rest.

References

  1. Do Fish Sleep? Retrieved from: oceanservice.noa.gov
  2. Do Fish Sleep? Retrieved from: sleep.org

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Comments

Eric Dockett (author) from USA on August 03, 2019:

@Samuel - Does your betta have another hiding spot in the tank? It sounds like he is trying to escape the light. I expect he'd get used to the light and come back out eventually, but you'll want him hiding somewhere besides behind the filter in the meantime. Just a guess.

Samuel James Campbell on August 02, 2019:

Hello,

Im new to fishkeeping, and got my first betta yesterday. However, whenever i turn on any light (room light or aquarium light), or open the window curtains, exposing a very little light to the tank, my betta immediately swims to the top of the tank and hides behind the filter.

Can anyone tell me what is happening? I think it might be stressed, but i am still very mew to this

LeslieAnne on April 23, 2019:

My Betta, Rico, definitely cat-naps during the day! (Fish-naps?)

He takes a minute or so to come out of his hidey spot, then comes up for food. If he thinks he's starving, he'll jump out of the water to take his food from my fingers!