Why Are Female Guppies Aggressive?

Female guppies are not aggressive by nature but will become aggressive under certain circumstances. Knowing those circumstances and preventing or minimizing their impact is essential for maintaining your guppy’s well-being.

Guppies are peaceful fish who are not designed to fight. Physical aggression may cause injuries and psychological stress, weakening their immune system and making them vulnerable to diseases and parasites.

But why do female guppies fight, and what can you do to prevent that behavior? Today’s article aims to bring some light into the matter.

The 5 Reasons Why a Female Guppy is Aggressive

Female guppies will fight for many reasons, but there are 5 that rule over the rest:

– Ensuring a Pecking Order

Female guppies have a strict pecking order to adhere to, which dictates the dynamics between the females. If a female disregards the pecking order, the ones ranking above it will enforce the rules.

Female guppies don’t resort to extreme violence because guppies aren’t built for that. But they will teach the rebel female a lesson by poking it and nipping at its fins. This will cause the bullied to retreat and seek hiding; lesson learned.

There’s nothing you can do here; the pecking order will exist whether you like it or not. All guppies will abide by it and structure their societies based on this hierarchical system. You should only intervene if guppies become overtly violent or display more aggressive behavior, even when unprovoked.

– Feeding Time

Guppies are particularly irritable during feeding. This aggressive attitude stems from their feral instincts telling the guppy that food is scarce. It’s a natural predisposition coming from living in a competitive environment for thousands of generations.

The fact that guppies like in an aquarium changes nothing since guppies are still feral by nature. This means that you can still see guppy females fighting over food under the influence of their primal instincts.

To mitigate this problem, try to feed guppies in separate pocket areas throughout the tank. Sprinkle some food in different parts of the aquarium, causing the guppies to disperse and minimize their eating interactions.

– Labor

Pregnant female guppies are notoriously more irritable, but the situation tends to degenerate fast when labor approaches. At that time, the female will seek to hide from the rest of the pack and might get aggressive towards other guppies, males especially.

The males’ persistency especially influences the female’s behavior since guppy males will often try to mate with the pregnant females. They never pay attention to details like an ongoing pregnancy.

This can cause the female to grow more aggressive and irritable than usual, as she will often snap at the males and attack them.

Important reminder: The males may end up stressing the female, which is why I recommend isolating the female when labor approaches. This will also grant you more control over the fry to come in case you decide to keep some or all of them.

– Overcrowded Tank

Overcrowding is an issue in all fish tanks, not only guppy ones. Overcrowding often leads to lower water oxygenation, elevated levels of fish waste, and a change in the fish’s behavior. Guppies don’t like tight and crowded places, making them irritable and stressed.

Both male and female guppies have powerful territorial instincts, which is why they don’t fare well in small tanks. To prevent any overcrowding-related problems, ensure a healthy fish-per-gallon ratio. According to the golden rule, every guppy should have at least 2 gallons of water available.

So, don’t keep more than 5 guppies in a 10-gallon tank. This ratio can change slightly if the guppies are a bit larger. I suggest providing each guppy with at least 2 gallons of water, ensuring their comfort and peace of mind.

This will minimize the stress and keep guppies calmer throughout the day.

– Lack of Hiding Places

Guppies don’t really like to fight with other tank inhabitants. They would rather avoid any conflict and look for hiding places in their environment. The ideal guppy habitat should contain freshwater, live plants, logs and driftwood, caves, rocks, etc.

All these decorations will provide guppies comfort, minimizing their unease in stressful situations. Many things can stress guppies, including aggressive or overtly playful tank mates, perceived threats, and even frequent commotion in the aquarium room.

Keeping guppies in a lush and fully decorated habitat will minimize their stress and lower their aggressive behavior.

Do Female Guppies Fight?

Yes, female guppies fight, but not too often, and they don’t show as much dedication as males do. Females typically resort to harassment rather than fighting, trying to get their point across. As I’ve explained, female guppies tend to fight for practical reasons, like food, ensuring the pecking order, protecting their pregnancy, etc.

Male guppies will primarily fight for territory, the right to mate with the females, and sometimes just because they can. Males love to impose their will on the weaker individuals of lower social status.

Are Female Guppies Territorial?

Yes, but not excessively. The territorial behavior is more prevalent in males, but females are not exempt from showing it either. This behavior will typically manifest via larger females bullying the smaller ones into hiding.

If your female guppies grow excessively territorial, I recommend either upgrading the tank’s size or isolating the abuser for a while. However, it’s unlikely that you will encounter this situation since females are generally calmer.

Why Does a Female Guppy Attack Males?

This will typically happen when the female is pregnant. Guppies mate every month, and the mating can last for several hours. During this time, the female guppy will mate with more than one male if more are available.

The problem is that the female guppy will reach a point when it’s done with the mating. Male guppies don’t have that off switch. As a result, they will keep pushing the females, chasing them around the tank, and stressing them out.

Females will often push back, becoming aggressive towards the males. Don’t worry, this is their way of controlling the situation and informing the males of their intentions.

You should only intervene if females show symptoms of stress due to the males’ persistency.


Female guppies aren’t aggressive by nature but will display aggressive behavior under certain conditions. Your role should be to assess each situation and determine whether you should intervene or not.

Guppies are generally peaceful fish, so all their queries will solve on their own. If they don’t, take control and find an adequate solution depending on the nature of each problem.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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