Water Bugs Vs Cockroaches (7 Key Differences)

Waterbugs are often mistaken for cockroaches. Water Bugs Vs Cockroaches Mistaking one bug for the other leads to wrong pest eradication interventions – get rid of cockroaches

Although they bare close resemblance, it is possible to differentiate the two based on some factors. I’ll take you through some of the features you can use to differentiate cockroaches (including baby roaches) from water-bugs.

Water Bugs Vs Cockroaches (7 Key Differences)

1. Appearance

Waterbug – The length of a giant waterbug is about 3.8 cm (1.5 inches) and it’s the one that is mostly confused for a cockroach. Some waterbugs can reach up to 10 cm (4 inches) long. They have an oval-shaped body and three pairs of legs.

The fore limbs are modified to have sharp claws which they use to pierce and hold on their prey. Waterbugs are dark brown in color, almost resembling a dead leaf. Related: Mold vs Mildew

Cockroach – Cockroaches are also oval in shape and possess three pairs of legs and one pair of antennae. Most cockroach species are relatively smaller than waterbugs. But at between 3.2 and 5.4 mm long, the American roach will most likely be mistaken for a waterbug.

The best way to differentiate an American roach from a waterbug is to look at the color. Generally, American roaches are reddish brown in color. They also have a distinct yellowish coloration on their head resembling figure 8. 

2. Location

Cockroaches – The German and American roach are the most common indoor cockroaches. They inhabit warm, humid and dark places especially where food is readily is available. You can find them in the kitchen, bathroom, near the sink, food stores, and cabinet among other places.

Roaches live near wet places because their body requires water on a regular basis. But since they are not aquatic, they won’t get into water. Only a few species of roaches are known to survive underwater for long. 

Waterbugs – Water bugs live outdoors especially in water or wet places. That’s where they get their name from. Stagnant water, leaking pipes or wet surfaces around the compound make ideal places for them to thrive and reproduce.

Their ability to adapt to aquatic conditions is made possible by the presence of a respiratory tube (siphon). Now and then they stick the siphon out of the water to breathe in some air which they store in a small chamber.

It is this air that they use to breathe when hunting for prey under the water. Since only a small amount of air can be stored at a time, they regularly come near surface to refill.

3. Life Cycle

Cockroaches – Roaches develop from eggs to larvae then to adult. Depending on the species, females lay 10-40 eggs. The eggs are contained in a protective casing usually referred as an ootheca.

The egg incubation period ranges between 20 and 60 days for different roach species. Adult roaches can live up 180 days.

Waterbugs – A giant waterbug goes through egg-nymph-adult stages. A female lays eggs on things just able the water level. Eggs hatch into adults within 1 or 2 months and the adults live for 3 to 4 years. 

4. Diet

Cockroaches – The diet of a cockroach mainly consists of food substances especially those that contain sugar, fat and starch. That’s why they like clinging around your kitchen. However, in the absence of food substances, they’ll feed on almost anything including decaying matter, hair, dead skin, small insects, books and so on.

In the case of insects, they don’t go hunting but will eat any insect they find on their way.

Waterbugs – Unlike roaches, waterbugs are omnivorous insects which survive mainly by eating aquatic insects, small reptiles, tiny fish and amphibians. They kill their prey by hunting it down and sucking their internal organs using a digesting enzyme.

Related: Cockroach Versus Palmetto Bug

5. Temperament

Waterbugs – Waterbugs are aggressive hunters of small aquatic creatures like fish, snails, frogs and so on. However, they won’t generally pursue humans to bite them. They only bite humans when they few threatened or when you invade their habitats.

If you walk in their territories barefooted, you may get a toe bite from waterbugs. For this reason, waterbugs are sometimes called ‘toe-biters’. Such bites are very painful but they won’t make you ill.

Cockroaches – Cockroaches are timid creatures and will always scamper for safety whenever exposed to light. Therefore, it’s very rare to sustain a cockroach bite. However, they can bite as they go about looking for food especially when there’s no alternative food.

You don’t have to be scared of roach bites! These creatures are always running away for humans or light.

6. Pest Threat

Cockroaches – Cockroaches are considered a pest threat when they invade our homes. They tend to contaminate our food as they scavenge for something to eat. Cockroaches are carriers of the salmonella bacteria which may be transmitted to humans when they touch their food.

Symptoms of Salmonella appear within 12-72 hours from the time of infection and may include fever, vomiting, diarrhoea and so on.

Roaches can also cause asthma through their fecal excrement and moulted skin.

Waterbugs – Waterbugs prefer outdoor conditions because they are attracted to dampness. However, they might come into your house in search of food or warmth. Although they are not know to cause a lot of havoc, they can also be considered as pests when they get to your house.

Unlike cockroaches, waterbugs are not associated with infections. The main concern with waterbugs is the risk of bites and asthma.

Related: What Do Roaches Smell Like?

How to Eradicate Cockroaches Vs Waterbugs

Waterbugs are easier to eradicate than cockroaches. That because roaches tend to be invasive and easily adapt to the environment for their survival. They also live in large colonies and reproduce rapidly.

1. Roach Baits 

However, both pests can be eradicated using the same methods. Below are some of the most effective remedies for cockroaches and waterbugs. 

Roach baits provide an easy and convenient way of eradicating waterbugs and cockroaches. The best roach baits contain attractants which lure the insects to the insecticide. Most of the popular roach bait brands contain a slow-acting ingredient which kills insects slowly. 

This technology ensures that the insects have enough time to share the poison with the rest of the colony. Such roach baits or  roach foggers will be ideal for eliminating a whole colony of roaches or waterbugs. 

Roach baits can be placed on various locations depending on their type. For instance, roach motels are ideal for low-laying places such as beneath the furniture. Roach gels are good for areas above the surface such as on walls and along baseboards.

2. Roach Spray

Roach sprays can be used to kill and repel roaches and waterbugs. Most of the best roach killers come as insecticide concentrates which require to be diluted with water and sprayed directly on the affected areas.

3. Boric Acid

Boric acid powder can be spread on the affected areas to kill roaches and waterbugs. This powder exists as microscopic particles which are able to break through the insect’s exoskeleton where it causes dehydration.

You can also make a solution by mixing boric acid powder with water. This solution can be applied by sprinkling or by using a spray bottle.

4. Vinegar

Vinegar can be used as a natural method for repelling roaches and waterbugs. Make a vinegar solution and spray on the affected areas to repel these creatures.

Although it won’t kill them, it forces them out of the place and deters them from coming back. However, due to its short lasting effect, you need to apply regularly to keep these creatures at bay. 

How to Prevent Waterbugs

Waterbugs will thrive in your compound and eventually find their way into your house. So, the best thing to do is to eliminate all possible avenues for breeding and thriving. Getting rid of wet conditions denies waterbugs a place to thrive and breed. Below are some steps you can follow to inhibit their survival.

  • If you suspect that you have a waterbug infestation, ensure that all possible pools of water inside the house are drained. These include pet water vessels, flower vessels, sink and so on.
  • Get rid of a pools of water around the compound. These may include rain water collection vessels, bird baths, and ground holes. For ground holes, you can fill them with soil.
  • If it’s raining, ensure that the flowing water does not get blocked by debris or items on your compound. The idea here is to reduce the ability of water to pool around. 

How to Prevent Cockroaches

Cockroaches come to your house in search of food, water and warmth. So, effective prevention measures must be geared towards eliminating anything that attracts roaches. Below are some tips for preventing cockroach infestation.

  • Keep your house clean and free from spilled food or crumbs.
  • Any cooked food should be kept in covered vessels or in the refrigerator
  • Always keep your utensils clean
  • Uncooked food should be locked in a properly sealed store
  • Dispose garbage regularly
  • Dustbins should have tight-fitting lids
  • Clean your sink after use to eliminate food particles
  • Clean your bathroom and kitchen with a disinfectant
  • Do not leave pools of water in your kitchen, bathroom or any other place.


Water bugs and cockroaches exhibit several similarities that might make it difficult to differentiate. This guide makes it very easy to differentiate the two common household pests.

One notable difference is the presence of sharp claws in waterbugs which is not the case with cockroaches. Correct pest identification enables you to embark on an effective eradication method.

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