Do Insects Have Brains?

For humans, our brains hold massive amounts of information. The same is true for animals of all sizes in all different climates. However, is the same true for insects? 

Insects do have brains. While insects’ brains are very small in size, their brains hold information that controls their senses. Additionally, it is understood that insects possess a rather complex set of senses.

The remainder of this article will explore a number of topics surrounding the insect brain. These topics will include the nervous system, senses, and whether or not insects are capable of dreaming or feeling emotions.

The Insect Brain

The brain of each insect is extremely small in size. Smaller brain-like organs known as ganglia can be found throughout the entirety of the insect’s body. Thanks to these highly intelligent nervous organs, the insect can adapt and react.

In fact, insects can feel, see, and smell at a much faster rate than humans. So what does this mean in terms of survival?

Due to the rapid rate at which insects’ brains are capable of processing information, insects such as sensing immediate threats or danger are heightened. This can make it extremely challenging for other animals to hunt and kill certain insects. 

Macro of ladybug head
Michele [email protected]

The Insect Nervous System

For insects, their nervous system consists of three parts: the peripheral, central, and visceral nervous systems. Specialized extensions of the nervous system known as axons and dendrites work together to transport information throughout the insects’ nervous system. While dendrites bring information toward the soma, axons carry that information away. 

The entirety of the insect’s nervous system consists of many moving parts, all of which are vital to the insects’ survival. Without the nervous system, the insect’s brain would be unable to function properly in terms of memory, motor skills, and instincts.

Do Insects Have a Sense of Smell?

Unlike humans and other mammals, insects do not have noses. However, insects are capable of detecting certain scents. This basic sense of smell is accomplished thanks to the insects’ antennae. 

When paired with other sensory organs, these antennae allow insects to find mates, avoid predators, locate food sources, and gather into groups. Chemical signals, known as pheromones, indicate specific scents to the insects’ sensory organs. 

Pheromones are taken in at the porous surface of the antennae and release at nerve endings. This process is just one example of insects communicating amongst themselves through chemical signals. 

Do Insects Have a Sense of Sight?

Much like the human eye, an insect’s eyes consist of a retina, cornea, and optic nerve. Insects’ eyes are sensitive to both color and light as well. The insect eye is capable of detecting a wider spectrum than people. Some insects are even able to detect ultraviolet light visually. 

In compound eyes, for example, photoreceptors are used to detect the quality and presence of light. This process is known as electromagnetic radiation. Thanks to this process, insects of all kinds can visually interpret and understand their exact surroundings. This sense of sight allows insects to navigate through their environments successfully. 

This sense of sight comes in especially handy when insects, such as ants, venture away from their nests. Leaving the nest for extended periods of time is essential to the insects’ survival because they need to search for food and supplies. Because of their ability to visually understand their surroundings, insects can return to their nests with all of the supplies that are crucial to survival. 

Do Insects Have a Sense of Hearing?

For insects, the ability to hear only exists in a few orders: 

  • Diptera (flies)
  • Lepidoptera (moths and butterflies)
  • Heteroptera
  • Homoptera (cicadas) 
  • Orthoptera (grasshoppers and crickets)

Much like humans and other mammals, orthoptera, such as grasshoppers and crickets, do have ears. These ears allow the insects to sense and perceive sounds successfully. 

Do Insects Have a Sense of Touch?

In humans, the sense of touch often protects us from physical harm. One of the most common examples relates to burning prevention. When the nerve endings on the surface of the human skin come into contact with a hot surface, like a stovetop, the response to quickly remove the skin from the surface is triggered.

Generally, sensory receptors are present in order for the insect to detect environmental changes so that they can respond accordingly. Avoidance reactions and cleaning behavior are the two most commonly triggered responses. Irritant compounds such as ammonia or acids are capable of triggering these reactions. 

Do Insects Have a Sense of Taste?

Thanks to chemoreceptors, insects can detect the presence of certain substrates in the air. In the case of a sense of taste, substrates are detected by chemoreceptors. 

Taste receptors, for insects, are most plentiful in the mouth region. Despite this fact, a number of taste receptors may also be found on the tarsi, genitalia, or antennae. 

Can Insects Dream?

Much like fish, insects are not capable of experiencing traditional dreams that humans experience. The type of dreams that humans experience is known as REM sleep. Though this concept of dreaming still has no known purpose, it is a common process in many birds and all mammals. 

Across all species who experience REM sleep, it is infants who dream the most frequently. For young dogs, REM sleep occurs roughly 20 minutes after falling asleep. This stage of sleep is by far the deepest sleep.

New neural connections are formed as a result of sensors becoming stimulated. This chemical reaction is responsible for triggering the portion of the brain that stores memory. For rats, their exact steps are re-traced during sleep. In certain songbirds, the precise melody of their tune is recited in their dreams. 

Can Insects Feel Emotions?

It is a common belief among entomologists that insects are not capable of feeling emotions. The insect brain is very simple in nature. Due to the simplicity of the insects’ brains, certain key regions that would process emotions are lacking. Humans possess the brain regions that are required for emotions to be felt. 

Despite their lack of traditional emotions, there is evidence that their consciousness can trigger the insects’ level of awareness. However, this level of awareness does not reach levels that are anywhere close to empathy, sadness, or joy, for example. 

Very early signs of emotion are present in some insects, such as grasshoppers. The most prominent emotion that can be associated with grasshoppers is nervousness. When winds blow or an animal approaches, the grasshopper would become nervous and jump or fly away. The same is true in flies. However, this emotion can be most closely associated with fright. 

The fact that insects are unable to communicate with humans through speech or written communication prevents scientists from reaching conclusions on the extent to which insects can feel emotions. 

Conclusion

While insects do have brains, their brains function differently compared to human brains, for example. Despite this, insects can possess a sense of sight, touch, hearing, taste, and smell. 

Some insects, however, are capable of feeling very basic emotions. It can not be concluded that insects consistently experience traditional emotions until insects can communicate with humans. 

Insect brains are simple in nature. However, they are built to perform basic circulatory and motor functions. These are two of the most vital aspects of the survival of the insect. 

Sources