Do Roaches Have Blood?

Adult Cockroach lying aside blood dropsCockroaches have blood, but it isn’t like what we have an imagination of. The roach blood is a colorless white fluid called hemolymph with hemocytes.

Hemolymph is a creamy, pale yellow, orange, and white fluid which transports vital nutrients to the tissues and organs. The color of the blood heavily depends on the sex of the roach.

For example, female egg-laying roaches have orange hemolymph, while male cockroaches usually have colorless blood. This is why you see a white fluid oozing from the body when you stomp a bug.

But why do these bugs don’t have the usual red-colored blood? These insects do not bleed like other insects or animals as they have an open circulatory system lacking arterial and venous blood supply. Instead, their body cavity contains the white goop-type blood in which the organs and tissues bathe.

Let’s learn more about the blood in roaches, its functions, and why it is colorless.

What Is the Blood of Cockroaches Called?

The blood of cockroaches is usually called hemolymph, which is present in their hemocoel. It is the primary body cavity that contains circulatory fluid in most invertebrates.

Cockroaches have an open circulatory system comprising visceral organs, which bathe in the hemocoel.

The roach blood in the hemocoel is a colorless liquid made up of plasma and hemocytes, which impart a white color to the blood. Sometimes cockroaches bleed out yellow or orangish blood as well.

What Kind of Blood Do Roaches Have?

The blood or hemolymph of cockroaches is a distinct type of blood. It is a colorless white fluid flowing through the roach’s body, similar to the blood of other insects.

Hemolymph is the white extracellular fluid that flows through the roach’s body. This fluid acts as blood for insects. The white blood is present in cockroaches, beetles, flies, and other types of arthropods.

It transports hormones, nutrients, nucleating agents, and waste between the cells. This fluid makes up about 15% to 75% of a roach’s body volume.

Hemolymph contains up to 50% water, while the remaining solution consists of organic compounds and salts. Due to these components, the roach blood appears white or colorless.

The color of the blood varies. It heavily depends on the sex of the cockroach. For example, male cockroaches have colorless transparent blood, while female cockroaches may have orange blood.

Components of Roach Blood

According to Comprehensive Molecular Insect Science, the roach blood hemolymph is a solution of inorganic salts, ions, organic compounds, and water.

There are three types of cells in the blood supply of a cockroach.

  1. Cells with vacuoles
  2. Limited tubule membrane cells
  3. High numerical membrane cells

These colorless cells impart colorlessness to the cockroach’s blood. Besides this, the roach blood also has a high concentration of the following components:

  • Amino acids
  • Lipids
  • Carbohydrates
  • Proteins
  • Glycerol
  • 20-50% water
  • Other organic and inorganic compounds

What Is the Role of Roach Blood?

Roach blood transports nutrients to the body, stores water, disposes waste products, and boosts immunity.

Unlike vertebrates, roaches do not need blood for oxygen transport. Therefore gaseous exchange does not take place through hemolymph.

Hemolymph only contains hemocytes that have a significant role in boosting the roach’s immunity, protecting the cockroach from pathogens. These cells also trigger cell genesis and repair damaged tissues.

Can Cockroaches Bleed to Death?

Cockroaches do not bleed out even if you accidentally stomp over a roach. Even wounded roaches do not bleed out to death because they have an open circulatory system that distributes colorless blood throughout the body.

This means that roaches lack a network of blood capillaries, arteries, and veins. Due to this, even decapitated cockroaches do not bleed out. Besides this, the hemocoel does not have pumped blood.

Instead, the blood floats around the hemocoel, and the vital tissues and organs flow into it. Therefore, roaches do not bleed out due to the lack of pressure present in hemolymph circulation.

The roach’s blood also contains hemocytes, ensuring clotting after a cockroach suffers a wound.

Cockroaches Can Even Live Without the Head!

Are you thinking of a zombie roach? If so, your mind is in the right place. Even if you chop off a roach’s head, it doesn’t bleed to death like humans. Instead, they survive many days without their heads since they don’t possess the same blood circulation system as humans.

Their open circulatory system poses less pressure on the wounded area. This way, the wound closes up instantly instead of bleeding to death.

Why Is Roach Blood Yellow/White?

Roach blood is white or yellow because it lacks hemoglobin, the iron-rich protein imparting red color to mammalian blood. Hemoglobin transports oxygen in the blood. But roach blood does not transport oxygen.

The tracheal system in cockroaches is responsible for transporting oxygen to the cells. Therefore, their blood lacks red hemoglobin and appears yellow/white.

Does White Blood Carry Nutrients?

White blood in cockroaches does not transport oxygen but supplies vital nutrients to the body. The open circulatory system allows the hemolymph to carry nutrients and waste materials without oxygen. This endolymph directly bathes the organs to transport nutrients to the roach.

Why Is Cockroach Blood Orange?

Mostly, the roach blood is colorless, white, or transparent. But you might stumble across a roach with orange blood because of certain factors, such as hormonal change.

Both male and female roaches have colorless blood. But the color of hemolymph may change in female cockroaches during their egg-laying cycle. Additionally, adult female bugs experience hormonal changes when they produce eggs.

The hormonal changes trigger the roach’s liver to generate vitellogenin, a yellow-orange protein. When the blood bonds with vitellogenin, it turns orange. The hemolymph stays orange throughout the roach’s egg-laying cycle.


Do Baby Roaches Have Blood?

Baby roaches have blood just like adult roaches. However, roach nymphs have a higher concentration of hemolymph in their body than adult roaches, as it is vital for providing nutrients to the growing cockroach.

Is Cockroach Blood Harmful to Humans?

Cockroach blood is not harmful to humans if they come in contact with it. However, it contains many allergens. These allergens are present in the roach’s saliva, feces, and blood. About 30% to 60% of people suffer from allergies due to roaches, but the allergens are not present in the roach’s bodies. Therefore, they are not linked to the blood directly.

Can Cockroach Blood Cause Infections in Humans?

Cockroach blood can cause moderate infections in humans as allergens and bacteria present on the roach’s body can quickly spread to humans via cockroach blood. Cockroaches contain about 30 bacteria, including salmonella and E.Coli.

Besides this, some parasitic worms also infect roaches. These can spread to humans through blood contact or accidental ingestion.

Can Roaches Survive Without Blood?

Cockroaches may not bleed uncontrollably, but they cannot survive without blood. Hemolymph is vital for transporting nutrients and removing poisons from the roach.

If cockroaches do not have hemolymph, their cells and tissues will cease to work properly, resulting in death.

However, if a cockroach survives a head injury, immediate clotting seals the neck, preventing the organism’s death as the blood supply is still efficient in the body cavity.

Why Do Some Roaches Bleed Red?

Some roaches bleed red due to vitellogenin, an orange compound in female cockroaches, to provide nutrients to eggs. However, the blood with vitellogenin is more orange than red.

Can Roaches Die From Blood Loss?

Cockroaches are resilient creatures that do not die from blood loss. In addition, they are challenging to kill due to their hard exoskeleton.

Even if cockroaches are wounded or injured, they are not susceptible to bleeding. This is because their open circulatory system does not have interconnected veins and arteries. Therefore, they do not lose blood even when they are injured.

Cockroaches can even survive without their head for a few weeks. This means that even if a roach is decapitated, it won’t die from blood loss. Only a little hemolymph oozes out of the wound, but most of the time, cockroaches survive injuries and do not bleed to death.


Cockroach blood is not crimson, unlike humans, as it does not contain the red respiratory pigment called hemoglobin. Instead, cockroaches have a pale, creamy, yellow-whitish blood called hemolymph.

Here is a brief takeaway of what we learned about the cockroach’s blood, its functions, and its significance:

  • Hemocytes and three other types of cells are responsible for imparting the white color to hemolymph.
  • Hemolymph transports nutrients to the body and removes waste materials.
  • Cockroaches lack arterial and venous blood supply. Instead, their body cavity contains an open circulatory system due to which their organs bathe in the hemolymph.
  • Roaches do not instantly die if they are decapitated as hemocytes in hemolymph immediately clot the blood to seal the neck.
  • Cockroaches don’t bleed to death. Instead, their blood pressure system closes up their wounds instantly, allowing them to live without their head for days.
  • The white blood is vital for the roach to survive as it helps remove toxins and provides nutrients for survival, growth, and development.
  • The color of roaches’ blood varies from orange, yellow, white, and no color. It typically depends on the roaches’ sex, environment, and hormonal changes.