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There are over 18,500 identified species of butterflies in the world. They can be found in all parts of the world, in all countries. However, despite being seen so often, most people do not know much about butterflies. This article answers one important question that all children have: do butterflies have bones? 

No, but they do have a skeletal system.

Butterfly Skeletal System

Butterfly Skeletal System

Fascinatingly, many parts of the butterfly’s skeletal system are similar to humans’. As a result, if you know a few parts of the human skeletal system, you may find it easier to understand the butterfly’s skeletal system.


Human bones are made of collagen and calcium phosphate – which is why calcium is necessary for the diet. In contrast, a butterfly’s bones are made of a material called chitin. Chitin is a large polysaccharide that is made from glucose. That is sugar. As a result, a butterfly’s bones are often made from a modified version of chitin. 

Do Butterflies Have Bones?

The thickness of chitin varies throughout the body of the butterfly. For parts that are very vulnerable or delicate, the chitin is thicker to protect them. For example, chitin is thicker near the head and the abdomen. For parts that are not very delicate, the layer is thinner.

The head

The head of the butterfly is one of the two vulnerable parts of the butterfly. Since the butterfly’s head is responsible for all functions, it is protected by a thick layer of chitin. The chitin here is in the form of a hard shell, much like our skull, and protects the tiny brain. The shell also has a similar structure to ours since the shell has holes – for the eyes, the antenna, and the proboscis.

The head of the butterfly is also called the gumdrop. As aforementioned, there are three important parts of the skeletal system. The first is the eye. A butterfly has two eyes. However, each eye is a compound eye with hundreds of lenses, giving it a 360-degree view of the environment. The second part that the skeleton protects is the proboscis. The proboscis is a straw-like tube. This tube is usually folded inside the skeleton between the eyes. 

However, it extends when the butterfly is ready to eat or wants to drink water. The last part that the head protects is the antenna. The antenna extends from the top of the head. They are also located between the eyes. However, these act as the butterfly’s nose. They help balance during flight and help find food and mates.

The abdomen


The abdomen is the second and the most important part of the butterfly. This part contains all the important organs in the butterfly, such as the heart, the breathing pores, the digestive system, and the reproductive organs. Because there are so many organs in this region, the chitin in this area is also very thick. 

The chitin in this part is like a suit of armour. It is made of 10 individual pieces locked into each other. However, each organ gets its suit of armour. As a result, there are 10 individual rings on the body of the butterfly. The chitin armour is thicker for some organs, which means the ring is thicker. In some, it is normal-sized, which means the ring is thinner or normal size.

This is regarded as the hardest portion of the butterfly’s skeletal system – even harder than the head. The reproductive organs and the heart are nestled in one or more of the rings in this region. As a result, the skeleton needs to be extra strong to ensure the body is not harmed during flight. 

However, because these organs also need to be used while reproducing, the armour cannot be stiff. This is why the butterfly doesn’t have one long armour but has an armour made of individual rings. These flexible joints allow the butterfly more flexibility during flight and reproduction while still protecting the organs.

The thorax

The thorax or the upper body of the butterfly gives the butterfly the power it needs to fly. Compared to the head of the butterfly and its abdomen, the thorax is quite tiny. Here, the chitin is specially evolved to protect the tiny muscles that power the wings. If exposed, these muscles would be crushed, resulting in the butterfly’s death.

The wings

The wings

Lastly, the wings. Surprisingly, even though these parts of the butterfly are delicate, they are also covered by the exoskeleton. Here, instead of one large skeleton, the protective layer becomes thin. While wings are necessary for the butterfly to fly, they are not protected by a thick skeleton. This is because a thick skeleton may hinder the flight of the butterfly. It can also cause balance issues or make it difficult for the butterfly to fly to higher heights.

One common misunderstanding is that the butterfly’s wings look like skin or are in one part. Instead, the exoskeleton here is also made from tiny plates that resemble the scales of a fish. This is often not seen unless you pay attention very carefully. They are as tiny as dust particles. Furthermore, because they are this tiny, they can be broken or dislodged very easily, making the butterfly very vulnerable in this region.

These are the five parts of the exoskeleton of a butterfly. 

What type of bone does a butterfly have?

One major difference between the human skeletal system and a butterfly’s skeletal system is that the human skeletal system is inside while the butterfly’s skeletal system is outside. As a result, butterflies are called exoskeletal. Under this skeletal system are the organs, muscles, and tissues of the butterfly. Therefore, butterflies have one large bone or exoskeleton that varies in thickness depending upon which part or organ it needs to protect.


This article breaks down all the important aspects of a butterfly’s skeletal system to help you learn more! Therefore, the answer to the question: do butterflies have bones? Is simple. They don’t have bones, but they do have an exoskeleton! If you’re looking for more such articles, visit our website to learn more.

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