No, ants do not have bones or endoskeletons (internal skeletons). Instead, they have exoskeletons (external skeletons). These exoskeletons provide structural support and shape to their bodies. They also protect them from drying out and physical harm.
In this article, we’ll learn more about the ant skeletal system as we discuss the following:
- What are bones
- Why ants don’t have bones
- What is an exoskeleton?
- Advantages and disadvantages of exoskeletons
What Are Bones Anyway?
Bones are rigid body tissues consisting of cells embedded in hard intercellular material. Its functions include structural support and protection of soft tissues and organs. They’re only found in the skeletal system of vertebrates. 
Why Don’t Ants Have Bones?
Ants don’t have bones because they’re invertebrates. They belong to a category of animals that don’t have backbones or bony structures. Instead, invertebrates have either hydrostatic skeletons or exoskeletons.
The former is a skeleton formed by a fluid-filled compartment called the coelom. It’s typically found in soft-bodied animals such as Cnidarians and earthworms.
The latter, on the other hand, is a skeletal system that features an exoskeleton. This system is commonly found in arthropods like ants. See this article to learn more about ants as arthropods.
What Is An Exoskeleton?
An exoskeleton is a rigid external encasement found in the exterior of arthropods. Similar to bones or an endoskeleton, they support and protect the soft tissues and organs of the body. Furthermore, exoskeletons have waterproof properties and help prevent desiccation or drying out. 
The exoskeleton is a multi-layered structure. It consists of 4 different layers, both living and non-living. 
These layers are as follows:
The epicuticle is the top or outermost layer of the exoskeleton. Its primary function is to prevent water loss and block the invasion of foreign bodies.
It’s subsequently composed of 3 more layers. The innermost layer is the cuticulin layer. This layer is composed of lipoproteins and fatty acids. It extends over the entire body and serves as a barrier for chemicals during molting.
On top of the cuticulin is a wax layer. This layer serves as the barrier to the movement of water into or out of the ant’s body.
Finally, the top layer of the epicuticle is the cement layer. This layer keeps the wax layer intact and protects it from abrasion.
The next layer is the procuticle. This layer is primarily made of a tough fibrous material called chitin. This material is similar to the cellulose of plant cell walls. It provides the exoskeleton with hardness and rigidity to protect the body.
The procuticle consists of 2 layers, a hard, outer exocuticle, and a soft, inner endocuticle.
Below the procuticle is a living cellular layer called the epidermis. This layer secretes the non-living cuticle that lies above it. It also produces part of the basement layer below.
Following the epidermis is the basement layer. This layer supports the epidermal cells. They also separate the ant’s body cavity from the exoskeleton.
Advantages Of Exoskeletons
The primary advantage of having an exoskeleton is the protection that it provides. They’re basically body armor. They can deform and absorb physical blows to protect the ant’s internal structures.
Additionally, they also help prevent desiccation and invasion of foreign bodies.
Disadvantages Of Exoskeletons
As exoskeletons are rigid, they can’t stretch to accommodate growth. Because of this, ants have to molt or shed their exoskeletons to grow and develop. Check this article to learn more about ants molting.
When they do, they become extremely vulnerable to predators. They essentially can’t move while molting. Additionally, they will lack protection for some time as their new exoskeletons harden. 
Apart from that, chemical imbalances and other factors can cause issues while molting. These may cause mutilation and sometimes result in death.
Another disadvantage is the fact that exoskeletons limit size. This prevents ants from developing more complex structures. These structures may provide them with adaptive advantages. They may also allow ants access to a wider range of prey more prey. 
That said, there are some advantages that come with being smaller. Small creatures tend to survive large calamities. So, it’s actually more of a double-edged sword.
Do Ants Have Spines?
No, ants don’t have spines. Again, ants are invertebrates. Invertebrates don’t have spines or any other bones.
Do Ants Have Teeth?
Ants have external teeth attached to their mandibles. These teeth are strong and sharp. Ants use them to transport food items, and process food. They also use them to defend themselves and decapitate or dismember prey.
Summary: Do Ants Have Bones?
To summarize, no ants don’t have bones. Ants are invertebrates. This means that they have internal skeletons. Instead, they have hard rigid exoskeletons. These exoskeletons are primarily composed of chitin. They support and protect their bodies.