Why Do Water Bugs Come Out At Night?

According to the Canadian Journal of Zoology, water bugs are aquatic insects that live in freshwater ponds, slow-moving water bodies, and marshes.

These nasty insects are more likely to come out during summer because of the dryness of water resources around their natural habitat.

However, if you found a water bug last night in your home, then it is more likely that you might have tackled an oriental cockroach.

People often confuse oriental cockroaches with water bugshese both insects resemble quite a bit.

Therefore, in this guide, I’ll answer the “Why do water bugs come out at night?” and how to get rid of water bug infestation.

So, let’s get started:

Getting To Know Water Bugs

Before we dive deep, let’s start with knowing these pesky insects.

Also check: Beetle vs. Cockroach

Water bugs belong to the suborder Heteroptera under the infraorders Gerromorpha, Leptopodomorpha, and Nepomorpha.

The latter contains around 2,000 species, referred to as true water bugs.

Below is the image of a true water bug:

This category also includes backswimmers, toad bugs, adult water bugs, scorpions, and giant water bugs.

However, the commonly found water bugs around homes are often confused with oriental cockroaches due to following reasons:

  • Oriental cockroaches and American cockroaches also prefer living in wet and humid environments
  • And due to the resemblance of the physical appearance of oriental cockroaches and water bugs

To make it more straightforward, let’s look at the physical appearance of the water bugs.

Body Size

Water bugs have a body size of around 2 to 4 inches, slightly larger than the common cockroaches lurking around the kitchen or laundry room in your home.

Also, according to U.S National Park Service, the largest species of giant water bug can exceed a body size of 4.5- inches long (~ 12 cm).

Therefore, these nasty insects are more likely to be identified due to their body size.

Body Shape

Water bugs have slightly larger body sizes, flattened legs, and a large and round body shape.

They are slightly different from oval and flat body shapes, likewise in the case of cockroaches.


Like cockroaches, water bugs also have an antenna on their body, but it is comparatively shorter than cockroaches.

Therefore, you can quickly identify a male water bug if you observe a shorter antenna.


One of the significant reasons you will catch a water bug easily is its color.

Unlike a cockroach, you will find a water bug’s body color, likely dark brown or gray.

Also, remember that a water bug has wings on its back that are the same color as its body.


As said earlier, water bugs are most likely found near freshwater ponds, slow-moving pools, marshes, wet sewers, basements, and around water resources.

However, suppose the water resource around the natural habitat of water bugs gets empty or dry (during summer). In that case, water bugs leave their habitat to somewhere else where they can find water and food for survival.

It is why during summers, water bugs come out the most.

Reason For Water Bugs Coming Out At Night

Well, there is no great reason these nasty insects come out at night.

Unlike German or other cockroaches, water bugs are not prey insects; they actively hunt for food.

These water bugs also hunt in the daytime but mostly stay active during the nighttime.

It is why water bugs come out at night and you are more likely to find water bugs at nighttime.

However, confusing water bugs with oriental cockroaches remains one of the common reasons for finding water bugs more often during the night.

Do Water Bugs Fly?

Water bugs do fly.

And both males and females can fly with their wings.

These tiny creatures prefer to live more around the kitchen or bathroom, as they love to stay around water and food resources.

However, if you find more water bugs in your house at night, it can probably be due to artificial lights.

It is because water bugs are attracted to artificial lights.

Do Water Bugs Bite?

Giant water bugs are pretty similar to cockroaches in playing dead.

Once they encounter a human or any danger, they will try to play dead by excreting a substance from their anus.

The giant water bugs do this to give an illusion of death.

However, they do this to save themselves from danger.

But if they are aggressive, they will raise their front and hind legs.

And if you are unlucky enough and couldn’t get these warning signs, water bugs can bite.

The bite of a water bug is painful and can lead to swelling.

However, the symptoms are gone within some hours without any severe effects.

Also, they are known to carry no parasites or diseases, unlike cockroaches.

How To Treat A Giant Water Bug Bite?

If a giant water bug bites you, you might feel a burning sensation at the sting site and itching, redness, and swelling with mild pain.

Even though water bug bite is not that much concern to humans but still to be on the safe side, you can always treat water bug bite by following methods:

  • You can mix turmeric powder and water to form a paste and apply it on the sting site for betterment.
  • You can also apply aloe vera gel to human skin to reduce the burning sensation.
  • Applying cold compresses can also work.
  • You can also apply a general insect bite cream or gel if you have one.
  • Some people also prefer applying cooking oil or peppermint oil.

However, you should consult a medical professional immediately if the reactions or symptoms become severe.

Where Do Water Bugs Live?

As mentioned earlier, water bugs are aquatic insects living in freshwater ponds, marshes, and slow-moving pools, where they can typically hide underwater, vegetation, and debris.

Further, these tiny insects are also attracted to bright lights.

That means they can also seek bright lights in your home, neon signs, or street lights.

However, if the water bugs are removed from the water and exposed to danger, they behave like roaches.

They will start pretending to be dead, and to make it more realistic, and they also excrete some substances from their anus.

This defensive action is also seen in the cockroaches when they turn upside down to fake their death and save themselves from danger.

Once it is safe, the water bugs will return to life.

Like water bugs, oriental cockroaches are also a species of roaches that love to stay around drains and sewers.

Therefore, oriental cockroaches are often confused with water bugs.

Do Water Bugs Look Like Cockroaches?

Although species-wise, cockroaches and water bugs are different, however, appearance-wise, they might resemble some traits.

For example, from afar, the size of cockroaches and water bugs can be confused.

Having an antenna on the head of water bugs and cockroaches also makes them appear similar though water bugs have a smaller antennae.

However, the color of these insects’ bodies sets them apart.

For instance, cockroaches have mainly four varieties of shades. These are:

  • Reddish-brown
  • Light brown
  • Black
  • Mahogany

These are the most common color shades that are found on common cockroaches.

On the other hand, water bugs typically have brown or grayish color shades.

However, in some cases, cockroaches also have yellow or cream bands around the head area, which water bugs don’t have.

Water bugs commonly have body colors similar to the dead leaf, entirely different from the color of commonly found cockroaches.

What Are The Differences Between Water Bugs And Cockroaches?

Apart from similarities, water bugs and cockroaches have various differences.

Their significant differences are as mentioned below:

  • Water bugs are more likely to live around standing water, ponds, and marshes, whereas cockroaches live around the kitchen in homes, bathrooms, and even the wood area.
  • Water bugs have shorter antennas on their heads, while cockroaches have more giant antennae.
  • Water bugs have slightly larger body sizes compared to cockroaches.
  • Cockroaches are prey insects, but water bugs are predators and can feed on the juices of small fish and tadpoles in the water.
  • Cockroaches are likelier to infest homes where they find food and water resources, but water bugs rarely colonize indoor dwellings.

Apart from these, the significant difference is that cockroaches do not like lighting and love to stay in dark and damp areas whereas waterbugs love artificial lights and thus come out at night mostly towards households.

On the other hand, water bugs are attracted to artificial lights; therefore, they also come out at night often.

Above all, once you know the right differences between these two insects, you can quickly identify any of them to ensure you get rid of them ASAP.

Water Bugs Infestation Vs. Cockroaches Infestation

The cockroach infestation in the home is a bad condition.

However, you might rarely have a water bug infestation because water bugs mostly don’t like to stay indoors.

On the other hand, if you find one or two roaches roaming in your home, it is more likely that your home might have more of them.

Therefore, treating cockroach infestation becomes essential as you might be in trouble due to the heavy infestation of roaches.

You can find our detailed guide here on How To Get Rid Of Cockroach Infestation Quickly?

Getting Rid of Water Bugs with CIAO: Clean, Inspect, Attack, and Outsmart Future Water Bugs

Even though water bug infestation in the home is rare (thanks to cockroaches for taking this responsibility!), somehow, if you got a water bug infestation, then this is how you can get rid of them.

Any bug living in your home is not easy to eliminate if you are not taking action.

Therefore, the CIAO action plan stands for Clean, Inspect, Attack, and Outsmart.

However, if you regularly have pest issues in your home, then taking professional help from pest control companies such as IPM (Integrated Pest Management) works excellently.

It gives you a long-term solution to eliminate pests in your home.

However, as of now, we will look at our CIAO (Clean, Inspect, Attack, and Outsmart) action plan and how you can work on that.

1. Clean Your Home

Cleaning your home is the first step to keeping water bugs away, cockroaches, and other pests.

These tiny insects, such as water bugs, survive on the plenty of food crumbs and clutter that we leave behind and do not clean.

And by keeping your home clean, you can ensure that these bugs get starved by not getting any pet food, pieces, or crumbs.

It is the first step to eliminating water bugs and other pests from your home.

Also, by cleaning your home regularly, you get to know where these bugs are hiding, and then you can take the necessary steps to keep them away.

2. Inspect Your Home

The next step after cleaning or along with cleaning is to keep inspecting for the places where you can find the signs of water and bed bugs again.

After cleaning your home, it becomes easier to list areas where water bugs might be hiding.

While inspecting, you must keep your eyes on the moist areas where you have found some droppings, dead roaches, and dead bugs.

These are the most hotspot areas where you can likely find a colony of bugs.

By inspecting, you can learn about the hiding places of these bugs.

Once you have inspected your home correctly, you can start taking necessary action to eliminate them.

3. Attack Water Bugs

Once you have cleaned and inspected the places where the water bugs are hiding, you can start attacking them.

By attacking, we mean you can take the help of various techniques and methods to kill water bugs.

Various guides and blog posts are available on the internet where you can learn how to eliminate water bugs from your home.

However, the popular methods for killing water bugs at home are:

  • Gel bait (works for cockroaches too)
  • Boric acid powder
  • Baited traps
  • Insecticidal dust
  • Insect growth regulator (IGR)

After cleaning and inspecting, you have already come 50% of the way; therefore, it is time to attack these pesky bugs.

Catch them with gel bait, one of the most popular cockroach-catching methods.

Insecticidal dust works like magic, but you need to implement it on the affected area to make it work like magic.

Boric acid, silica, and diatomaceous earth are one of the standard solutions which can last long and spread widely.

To make it work effectively, you can apply a thin layer of dust in wall cavities and voids in basement walls where you doubt having water bugs the most.

Once stuck to the surfaces of bugs, these deadly particles dehydrate and kill them instantly.

However, remember that whenever using any chemical or powdery substance to kill tiny insects, keep them away from food items or children.

You can also avoid using these methods in the kitchen and can use them in other parts of the home.

4. Outsmart Water Bugs

Even after you have eliminated water bugs, you have to stay alert, as these nasty insects can re-infest your home again.

To stay alert, you must practice good habits such as cleaning, regular pest control, and proper waste management to keep water bugs away forever.

The ideal place for a water bug or cockroach is to find a warm and protected environment with enough food and water supply to thrive on.

You can outsmart these bugs by closing all their entry points, sealing up your food items, and cleaning any leftovers from wherever possible.

So, with these action plans, you can eliminate these nasty insects.

Effects Of A Severe Water Bug Infestation

Having a water bug infestation in the home is problematic as it can be the reason for various illnesses related to stomach, allergies, and even asthma attacks.

If you found a few water bugs in your home and think there’s nothing to be worried about as they are very few, then you may be wrong here.

These tiny insects can breed much faster and prepare a whole colony to create trouble for you.

Sometimes, things become so worse that it is not easy to handle unless you get a pest control professional to get rid of waterbugs.

Water bugs and cockroaches are pretty similar when it comes to breeding and infesting a home, but in the case of water bugs, it becomes less likely to face an infestation.

But if you get them in your home and don’t take the right action to eliminate them, they can cause several issues, from health to damaging properties.  

How to Prevent Water Bugs In Your Home?

Even if you have eliminated all of the bugs, you still need to stay aware and keep certain habits in practice, to prevent water bugs in your home.

These habits include regular home cleaning, waste management, and pest control.

However, apart from these, you can also follow these steps to keep water bugs away from your residence:

Stopping Water Leakages

Water bugs prefer staying near standing water.

Therefore, even though this might be the most obvious thing to do, most of us ignore it.

Water pipe leakages are among the most common reasons cockroaches and water bugs invade households.

If there is any water leakage in the kitchen or bathroom, get it repaired asap, as it might attract tiny insects.

Food and water are one of the primary reasons why water bugs prefer to stay indoors; therefore, by eliminating the one way, you can prevent them from your house.

Keeping Food Items Packed

Food is another crucial reason water bugs, and cockroaches get into your house. After eating, clean the table and leave no food crumbs.

Along with this, you also have to ensure your waste management system is working perfectly.

Leave no garbage outside or spill anywhere.

The ultimate purpose is to give no food source to the little bugs and clear all possible entry points.

How To Kill A Waterbug?

To kill a water bug there are many ways however, the most convenient ways are:

  • Catching them from gel baits and then killing them
  • Using sprays (most commonly used treatment).`
  • Using insecticide dust
  • Natural repellents
  • Sugar and baking soda mix

The first method works for cockroaches and other insects as well.

Once you catch these pesky insects, you can kill them by either directly slapping with some heavy object, burying them, or even using an insecticide spray bottle.

Though there are also many bug spray bottles available in the market.

However, if you are facing severe water bug pest infestation, getting a professional exterminator at work will be best.

The professional exterminator will get rid of most insects inside your home, and it will also be a long-term solution for this issue.

Some natural repellents also work to keep away these insects.

A mix of sugar and baking soda works perfectly to get rid of cockroaches, and you can also try to get rid of waterbugs with this technique.


How do you get rid of water bugs at night?

There are several ways to eliminate water bugs at night or day, and sprinkling boric acid may be the most effective solution to eliminate infestation.
However, many other products are available, too, for getting rid of these nasty insects.

Do water bugs crawl on beds?

Water bugs are more likely to come out at night to hunt food. However, they don’t bite humans usually nor approach a human.
But rarely, sometimes, they are known to crawl onto the beds at night.

What attracts Water bugs in the house?

Water bugs need a still source of water and food to thrive; therefore, they can quickly become pest infestations in your home if you provide them with these two resources in any way.

For example, if you have a pool that draws frogs, this can also be an invitation for water bugs.

Besides primary reasons, unlike cockroaches, water bugs tend to be attracted to electric light bulbs, and so are they called ‘electric light bugs.’

Final Words: Water Bugs Coming Out At Night

Now, you finally know why water bugs come out at night.

Water bugs are nasty, so you should keep them away from your home, whether at night or day.

Remember to keep your house clean and leaky pipes tight. Don’t provide any food resources so that water bugs find a reason to infest your home.

However, if you are facing an infestation, you can get rid of them quickly by following our solution guide or taking a professional help from an exterminator.

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