Do Betta Fish Kill and Eat Other Fish?

Betta fish are carnivores, also known to be aggressive and territorial. Since some species compatible with bettas are small and timid, you might wonder if bettas can attack, kill, and eat them.

Siamese fighting fish do not prey on other fish to eat them, but they may chase, nip, and attack other fish. Betta fish can kill another fish, usually by causing damage over time. Bettas can unintentionally swallow ill or tiny fish that fit into their mouths.

It is helpful to consider what bettas eat in nature to predict how they might view other fish in their aquariums.

Do Bettas Eat Other Fish in the Wild?

Although Siamese fighting fish are carnivores, smaller fish are not in bettas’ regular diet in their natural habitat in Southeast Asia.

Siamese fighting fish get the nutrients they need from the flesh and fiber of insects and crustaceans. The most common foods they consume include small shrimp and the larvae of mosquitos, bloodworms, and water fleas. Plant foods do not constitute a significant part of bettas’ diet.

If bettas have sufficient nutrition in nature or captivity, they do not eat other fish, at least not for sustenance.

Do Bettas Attack and Kill Other Fish?

Betta fish are territorial and aggressive and they are capable of killing other fish, especially in captivity.

Bettas in their natural habitats are not usually as aggressive as pet bettas. There are two main reasons for that:

Pet bettas were bred to be aggressive: people used to pit Siamese fighting fish against others to see them attack and kill for entertainment. Over time, aggressiveness became a characteristic trait.
Siamese fighting fish have ample room and resources in their natural habitats. Without the constraints of an aquarium, they do not need to be as territorial and defensive.

A defensive betta in a fish tank might not swallow and eat other fish but attack it continuously and nip its fins and tail. Even if the fish is large, an aggressive betta could kill the victim over time by causing constant injury.

Certain conditions make bettas more likely to act aggressively, and we’ll discuss those in the following sections.

Do Bettas Swallow Smaller Fish?

If you feed your Siamese fighting fish proper meat-based diets, betta will probably not view its tankmates as food.

Incidents when a betta eats another fish are likely to be caused by the following:

Unintentional swallowing, without any consideration of what is being eaten
Aggression and feeling defensive of territory and resources, eating the smaller fish out of aggression rather than for sustenance
Ill and slow-moving community fish are at risk of becoming an easy target, even if your betta is not preying on them

Can Bettas Live Together or with Other Fish?

WHAT TRIGGERS BETTA TO ATTACK OTHER FISH

Wrong Fish Combination in the Tank

Siamese fighting fish, especially males, often prefer to live alone. They are also very particular about their preferences for tankmates:

Two male bettas should not be housed together.
Females do better in a sorority of at least five fish. After the initial period of establishing their hierarchy, which may include chasing and nipping, the group lives peacefully.
In a community aquarium, the presence of other territorial species, for example, goldfish, can cause clashes regularly.
If the other fish in the tank have luxurious fins and tails or are bright and highly noticeable, a betta can become stressed out and triggered.
Top-dwelling fish will compete for space with betta because bettas spend most of their time in the middle and top portions of the aquarium.

Choosing the right tankmates for your betta or bettas will promote a peaceful environment in the community fish tank.

Passive fish that are not too small, such as Cory catfish, neon tetras, and simple guppies usually do well with female bettas.

Suboptimal Conditions in the Aquarium

Suboptimal conditions in the tank will affect the well-being and behavior of your fish and can cause conflicts.

Any sudden change in the environment or regular conditions that are not ideal for your fish can be a major stressor. Stress often triggers aggressive behaviors in fish, especially in bettas since they are territorial even in normal conditions.

Monitor the environment in your tank to make sure that the temperature, acidity, hardness, and bacterial composition are appropriate and stable for your bettas and any other fish or organisms living in the tank.

Overcrowding

Having too many fish in a small space is a major stressor that could lead to poor dynamics among the fish in your aquarium.

Observing fish interactions and adding new inhabitants to a fish tank can be exciting, especially for novice fish keepers. It is, however, imperative, to remember that overcrowding can become a stressor for all fish quickly and make it more difficult to keep the aquarium clean.

Fish need space and places to retreat to for rest, as well as things and space to explore.

Having hideout spots should be one of the first interventions if you notice that your pet fish fight. Bettas in particular are known to be curious and bright, so they need items and space to explore.

If betta attacks and nips a small enough fish, such as a guppy or tetra, it can end up killing and even eating them due to being territorial.

We dedicated a post to the aggressive behaviors of bettas and how to make a community tank with bettas a peaceful place. If you want to know more, you can follow this link on Betta’s feisty personality to learn more.

Bettas And Sick Fish

This is not specific to bettas: fish can eat specimens of their kind or other species, especially dying or ill fish.

There could be practical reasons for eating weaker fish, both their offspring or grown fish of their species.

Fish could be trying to prevent the spread of bacterial or viral infections by eliminating ill fellow fish. Fish that travel in schools might have to act this way to keep their entire group healthy.

This behavior persists in aquariums and it is not unusual for many fish species, including Bettas, to consume a sick tankmate.

Will Betta Fish Attack and Eat Snails in the Tank?

Bettas rarely attack and eat snails. They generally leave snails alone because snails stay out of betta’s way.

Snails’ shells also naturally protect them from any possible attack in the event a betta is tempted to go after them. That said, it is wise to avoid adding very small snails because they are more likely to become prey.

Why Do Pet Fish Nip Fins?

Usually, fish nip the fins and tails of others due to stress caused by something in their environment, often overcrowing or suboptimal water quality. However, one of the core factors of this behavior is genetic: some kinds of fish, including popular danios, bettas, and tetras, are more likely to respond to stressors by nipping their tankmates’ fins.