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Do Ants have Blood? (They have Hemoymph)

Ants do not have blood. They have something similar called hemolymph instead. It is like blood but instead of hemoglobin, the hemolymph is rich in hemocytes.

Hemolymph (insect blood) is a circulatory fluid that lacks red blood cells. When compared with the vertebrate blood they also have a higher amount of free amino acids in them.

carpenter ant

To have a closer look at the topic we are going to cover the following points:

  • A basic overview of the circulatory system in ants
  • A closer look at some of the functions of the hemolymph
  • A comparison between the human blood and the “ant blood”
  • Some of the prominent pros and cons of the ant circulatory system

So let’s dive right in…

Do Ants have a Heart and a Circulatory System?

Ants have a circulatory system in which the heart plays the central role, just like it does in our one. Hence they also have a highly active and genuine circulatory system in place. However, it is here that the similarities between our circulatory system and the ant circulatory system end.

The circulatory system of ants is of an ‘open’ type, which is totally different than our circulatory system, which is the ‘closed’ type. It is called an open circulatory system because the hemolymph (their version of blood) doesn’t need to flow only through the veins and arteries, it can flow freely throughout the body.

An Ant’s Circulatory System

Ants like all insects have an open circulatory system in place. Here, the heart is responsible for pumping the hemolymph (ant blood) hemocytes into a body cavity known as hemocoel. The hemolymph is rich in plasma and hemocytes. All the organs and body tissues of the ant are directly exposed to the hemolymph.

Body locomotion plays an important role in the flow of the hemolymph throughout the body. The relaxation of the heart helps in the backflow of the hemolymph into the heart from all over the body via “open-ended pores” (known as Ostia).


A Deeper Dive into the major functions of the Ant Circulatory system:

  • The main role of the hemolymph is to maintain a state of homeostatic equilibrium inside. This means it needs to regulate the levels of pH, lipids, proteins, ions, etc. with acute precision.
  • In insects, tracheal respiration is mainly responsible for the transport of oxygen and carbon dioxide within the body so the hemolymph plays a crucial role in the transport of nutrients, hormones, and wastes.
  • The insect blood or the hemolymph plays an important role in enhancing the immune response of the ants and in protection against harsh environmental-related issues. They contain cryoprotective agents that enhance the cold hardiness of the organism.
  • It also plays a vital role in wound healing and in acting as a supporting medium that holds the whole system below the hard exoskeleton together.

Is Ant Blood Red?

The blood of insects (hemolymph) such as ants is not red in color owing to the absence of the red blood cells.

It is the presence of hemoglobin in the red blood cells that gives the blood of the vertebrates, a deep red color.

So the absence of hemoglobin in the ant blood is the reason why it doesn’t have a red color.

Why don’t Ants have Red Blood Cells?

Hemoglobin plays a key role in the transport of oxygen from the lungs to all the cells and tissues.

However, in the ants, the respiration process is not carried out majorly by the hemolymph. Tracheal respiration plays an important role in that. Instead of hemoglobin, ants have got hemocyanin in the hemolymph which is a copper-based protein.

Graph: Hemolymph vs Blood

As there are no vessels, hemolymph directly bathes the organs.The blood travels throughout the body via vessels. It does not bathe the organs and tissues directly.
The nutrients are being directly transported within the tissues.The nutrients get transported to the respective tissues via the tissue fluid.
No transport of gases occurs.Gases are constantly transported and play an important role in respiration.
Blood flow is comparatively much slower.Blood flow is relatively way fast.
Here there is no control over the volume of blood that can flow to a particular place within the body.The blood flow is controlled heavily via the contraction and relaxation of the blood vessels.
The main component is hemocyanin.The main component is hemoglobin.

Advantages & Disadvantages of Open Circulatory Systems of Ants


1. It Tackles Heat Better

Open circulatory systems help in tackling heat way more efficiently than a closed circulatory system. As a result, ants can survive under extremely hot conditions with ease.

2. Low Blood Pressure

Owing to the absence of arteries and veins, the ant blood pressure is pretty low. As a result, these organisms can even exist in high-pressure environments with ease as sudden pressure changes don’t affect them.

3. Low Energy Consumption

When compared with the closed circulatory system of the vertebrates, the energy consumption of the open circulatory system is quite low.

As there are no arteries and veins, it takes a considerable amount of time for the ant blood to circulate properly. The low blood pressure rate is another reason why the blood takes longer to circulate.


1. Low Efficiency

The open circulatory system is only suited for smaller animals. Its input versus output ratio is quite low in comparison with the closed circulatory system.

2. Slow Metabolism

As oxygen transfer is mainly dependent on tracheal respiration and the energy consumption for hemolymph distribution is quite low, the speed of food digestion, waste removal is also much slower.


Are Ants Attracted to Blood?

bleeding finger

Any source of decaying protein is an attractive food option for ants. As long as the food source is rich in sugar and other nutrients, ants won’t discriminate among anything.

Blood is a treasure trove of nutrients and is rich in proteins, glucose, ions, vitamins, fat, etc. Hence it shouldn’t come as a surprise if you see ants getting attracted towards blood samples.

Read Deeper: Are Ants Attracted to Blood?


The majority of the animals which are up in the evolutionary ladder have a circulatory system in place. Ants are no exception to that rule. They are prominent members of the arthropod phylum.

Ants contain a fluid that is referred to as hemolymph instead of blood. It shares a lot of similarities with vertebrate blood but it doesn’t contain any erythrocytes which play an important role in the oxygen transfer in the vertebrate body and imparts a prominent red color to it.

The circulatory system of the ant is of open type. It doesn’t contain arteries and veins, so the blood pressure is quite low. However, it plays an important role in the transfer of nutrients throughout the body and keeps the overall system beneath the exoskeleton in perfect harmony.

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