Skip to Content

Do Moths Have Blood? (Answered)

Do Moths Have Blood? (Answered)

The anatomy of an insect is fascinating. Some share a few similarities to human anatomy.

Moreover, in all living things (invertebrates), blood is a general term that refers to a body fluid that helps the circulatory system perform optimally. So, you might be surprised to find out that a few creatures, which you did not expect to have blood, have this essential body liquid.

Moths, in this case, have fluid that works as human blood. However, it is not similar to mammals and a few other animals. For instance, it is not the ordinary red color; secondly, its content is not the same as human blood.

Luckily, this article sheds light on how moths use their circulatory system fluid to perform functions similar to blood in humans or a few other living organisms.

Read: Are Moths Blind?

Do Moths Have Blood?

Typically, moths have distinctive blood. However, it does not contain the same properties, nor is it colored red like human blood. This fluid is known as hemolymph and is usually yellowish or green. The key similarity is its importance in the moth’s body.

Moths, like other insects, need blood. This blood will facilitate the efficient transportation of nutrients throughout the moth’s body. Note that human blood helps circulate oxygen, nutrients from food, and waste in our bodies. Contrary to insect blood which does not do that. All insects absorb oxygen through thousands of tiny openings in their bodies known as spiracles.

If you have, at one point, accidentally squashed a moth at home, you might notice a thick white fluid oozing slowly from its body. Then that is insect blood.

Also, insect blood will clot the same way human blood does. So, if a moth has a minor injury, its blood will clot and heal after some time.

Lastly, the blood-like substance plays other significant roles, like molting and hatching in insects. For instance, the hydraulic pressure released helps a moth’s newly molted wings expand significantly when the heart pumps the hemolymph.

Do All Moths Have Blood?

Yes. All moths have something similar to blood. Remember that moths are insects and need a special fluid identical to blood to transport essential nutrients throughout their bodies. Furthermore, the quantity of the special fluid in a moth is significant to its size: the smaller the moth, the less the amount of blood.

Another surprising scenario to note is that moths have an open circulatory system. So, the hemolymph does not help in respiration. Instead, the blood-like fluid flows freely in its entire body, and the hundreds of spiracles help the moth absorb enough oxygen from the atmosphere.

Insects use hemolymph to regulate their body temperatures. For instance, the hemolymph circulates faster through the hundreds of tiny networks (similar to the veins and capillaries in humans) to connect the wings & legs to the abdomen, head, and other body parts. Conversely, the circulation slows significantly during cold weather.

Insects will also remove carbon dioxide from the hemocoel and absorb oxygen with the help of the spiracles. 

Do Moths Bleed?

Yes. Moths bleed. If you accidentally step on a moth or find it hurt in the bush, you can notice an odd-looking greenish or yellow solution oozing from its body. This substance is equivalent to blood in humans.

Remember that moths have a properly functioning nervous system and a uniquely-designed aorta. The aorta transmits hemolymph to the wings, brain, and other parts of a moth’s body to ensure the moth operates successfully.

Ordinarily, moths will hang motionless under leaves or a safe spot after hatching until their wings can function efficiently. Also, you must know that the hemolymph must circulate through the entire moth’s body before it can fly.

What is Hemolymph in Moths?

Hemolymph is a hemoglobin-like fluid that fills the entire body of an insect and facilitates the transportation of nutrients in an insect. Like human blood, the hemolymph is a yellowish-green fluid that you can see if you accidentally squash any insect.

The heart of a moth pushes the hemolymph around to ensure the proper functioning of the moth’s internal organs. Furthermore, hemolymph is not red because insects do not have red blood cells like most invertebrates.

Hemolymph in insects does not flow through the veins or arteries like blood in our bodies. However, it is absorbed in the insect’s tissues to help its reflexes.

Hemolymph, furthermore, is made up of plasmatic cells known as hemocytes. The hemocytes contain millions of tiny chemicals that help an insect’s immune system. The hemocytes engulf pathogens and bacteria to break them down into harmless chemical properties.

Scientists and researchers believe that hemocytes are similar to white blood cells in mammals.

Apart from supporting the internal organs of an insect. Other insects, like the blister beetles, use Hemolymph to protect themselves from predators. This beetle squirts the thick substance from its knees to repel predators.

Crickets use the hydraulic pressure pumped from its heart to create a reflex action on their legs that allows them to jump extreme heights.

What Color is Moth Blood?

The blood-like fluid in moths is usually greenish-yellow or pale blue in some species. Unlike human blood, this fluid does not contain red blood cells, thus its pale color. If you are keen, you can dissect a dead moth and observe this marvel.

The blood (Hemolymph) is necessary for a moth’s body to regulate its temperature. Similar to blood in humans, it circulates its entire body.

The blood is not only pale but contains amino acids, carbohydrates, proteins, and other nutrients essential for the development and functioning of internal organs.

Although yet to be proven, scientists believe that the greenish-yellow color pigment results from eating plants. Surprisingly, even blood-sucking moths have the same greenish-yellow fluid.

Do Moths Drink Blood?

No. Not all moths drink blood. However, one species known as the vampire moth (Calyptra thalictri), which belongs to the Erebidae family, is notorious for drinking animal blood. This species is native to Asia but can be spotted in Northern Europe.

The vampire moth has a proboscis that can pierce the tough hides of wild animals. Unfortunately, this moth can penetrate human skin without you noticing it.

Research has discovered that apart from sucking blood, the vampire moth can also suck fruit juice. Further analysis also discovered that the vampire moth could suck blood and related fluids for approximately 20 minutes before detaching its long proboscis from the host.

It is called mud-puddling when a vampire moth or other species seeks moisture from rotting fruits and other substances when the conditions are favorable.

Vampire moths prefer sucking blood to ingest nutrients like protein, calories, and sodium. Research has also revealed that they behave in that manner to pass the nutrients to the females during reproduction.

Do Moths Have Hearts?

Yes. Moths have hearts. Apart from sharing a few similarities and differences with humans, moths have a heart that is used to pump body fluid and help circulation throughout its body. Moreover, a moth’s nervous system functions best with an efficient circulation of this fluid.

The heart of a moth has a tube-like shape and is usually located in its dorsal section in the abdomen. Also, the heart has superficial vessels that perform similarly to the human heart.

The dorsal vessel is significant and integral in a moth’s heart. Typically, this vessel runs from the abdomen to the thorax to push the hemolymph to the head.

Also, you should know that the vessel chambers have muscles and ligaments that facilitate efficient pumping of the hemolymph.


In summary, insects (including moths) do not have the same blood as vertebrates. However, they have a blood-like fluid that works the same way as human blood.

So, the next time you see a grayish or greenish-yellow fluid oozing from an insect’s body, it is its hemolymph fluid. The liquid is not red because it does not contain red blood cells.