Difference Between Roaches and Water Bugs (With Table)

Insects have the largest population on Earth. They are fast-growing animals. Some of the widely seen insects are Roaches and Water bugs are two completely different sorts of insects, yet their appearances often lead to confusion. Roaches and water bugs have many similarities but they differ in some features.

Roaches vs Water Bugs

The main difference between roaches and water bugs is that roaches are terrestrial insects whereas water bugs are aquatic insects. Roaches are usually 1-1.5 inches in size while water bugs are 2 inches in size. Roaches are spotted in warm climatic conditions whereas water bugs are spotted in the water. Roaches have round body structures while water bugs have flat body structures.

Roaches are the insects that belong to the order Blattodea. They are terrestrial insects and their size can be up to 1-1.5 inches. They are usually spotted on land where the climate is hot and humid. Roaches are the large foragers that feed on nearly everything including leaves, wood pieces, parasites, algae, bugs, pieces of human foods.

The water bug is an insect that appears as though a cockroach (roaches), however isn’t a part of the roach family. A water bug is an aquatic insect that lives in water. Water bugs can pause their breathing for quite a while without reemerging. Whenever dealt with, water bugs can nibble in guard. Nonetheless, they hardly enter homes to search for food like roaches.

Comparison Table Between Roaches and Water Bugs

Parameters of Comparison


Water Bugs


1-1.5 inches in length

2 inches in length


Terrestrial insects

Aquatic insects


Warm places


Eating habits

Eats anything

Injects a dangerous enzyme into the prey


Runs away when comes across anything even when lights are on

Can bite who comes across

What is Roaches?

Roaches, popularly known as cockroaches are nocturnal terrestrial insects. They flourish in assorted conditions but prefer warm regions. Roaches have flat bodies and little heads. They have enormous eyes and long, antennae on each of the sides of their head. They also have two sets of wings. The external wings are hard for safety and the others are for flying purposes.

They leave their groups for mating. They find the food by the waste matter excreted by the other roaches. They for the most part assemble in swarms, liking to live respectively with different cockroaches in smaller regions. To draw in females for mating, male roaches sing an exceptional song and females are the ones who carry their eggs.

Even though roaches eat anything, they are not known to go after different insects. They like to eat plants, wood, paper, and other food sources. To shield themselves from hunters, insects show away from anything that pushes towards them.

For instance, they convey irresistible microorganisms. For example, Staphylococcus species and Streptococcus species, hepatitis infection, coliform microbes. In addition, they likewise convey microorganisms that cause food contamination, for example, Salmonella species, furthermore, Shigella spp. Likewise, they are connected with typhoid, looseness of the bowels, and cholera.

What is Water Bugs?

Water bugs are aquatic insects that are freshwater creatures that attach themselves to plants, linger in the mud, swim, or fly between bodies of water. Their body can be flat or rounded, and they have two pairs of wings, just like roaches. The antennae on their heads are short and slender. Some species do not have eyes, even though the majority do.

Their sizes and weights are similar to roaches, but they come in a wider range of hues, including black, blue, green, and brown. They generally live alone and associate with other water bugs just during the mating season wherein they dance on the outer layer of the water to draw in females. While the females for the most part convey the youthful, a few animal types have the males convey the eggs.

The enormous water bug, also known as toe biter, electric-light bug, or alligator tick is the most prevalent water bug species. They eat plants, and they additionally kill creatures like little fish and different crawlies for food. Like roaches, they additionally safeguard themselves by stowing away, however, they likewise can battle, cutting them with their platform.

Also, water bugs have a paddle-like foot structure, working with their development in the water. Likewise, they utilize a proboscis to infuse strong proteins into the prey to melt their inner parts so that water bug can suck out the fluid. Some water bugs will generally chomp people by their proboscis, and it is exceptionally painful. They are not considered to transmit any type of disease.

Main Differences Between Roaches and Water Bugs

  1. Roaches are nocturnal whereas water bugs are water-living insects.
  2. Roaches are 1 to 1.5 inches in size while water bugs are comparatively bigger ranging from 2 inches in size.
  3. Roaches ashore particularly in warm regions while water bugs live in water.
  4. Roaches fly away from light and anything that moves towards them but water bugs fight and bite their predators.
  5. Roaches have flat bodies with antennae whereas water bugs have round bodies and short antennae.
  6. Roaches don’t kill other insects but water bugs do kill other insects.
  7. Roaches live in groups while water bugs live alone and only reach out to other water bugs during mating.


Roaches are bug-like an insect with a 1-1.5 inches length body. Essentially, it is like living on the land. Additionally, it has a couple of slender and long antennas. Roaches are insects that spread diseases causing illness. Water bugs, on the other hand, are 2 inches in length. Roaches are also known as cockroaches have around 4600 species whereas 300 species of water bugs exist.

Water bugs are aquatic insects that live in water. They have shorter antennae as compared to the roaches. Sometimes, water bugs can also bite humans. However, for most of the part, they are predators of small insects. Accordingly, the fundamental contrast among water bugs and roaches differentiates between them with their size, habitat, temperament, and much more.


  1. https://muse.jhu.edu/article/663671/summary