Do Ants Feel Pain?

Scientists are Searching for the Answer

Ants are one of the most social animals on Earth. They are found on all continents except Antarctica. Scientists have estimated that there are over twenty quadrillion ants in the world. They build their colonies underground, within rotting trees, or under rocks. Ants work together as a colony to find food, care for the larvae, and protect their nest from predators. An ant is extremely small compared to a human; therefore, its nervous system is smaller. But if we pull a leg off an ant, or squish it, will it feel the same kind of pain we feel?

Table of Contents

The ant nervous system

An ant doesn’t have a brain like us. It has a cluster of nerves in the head and ganglia that run through the thorax and abdomen. Ganglia help with basic functions, like leg movements. A worker ant has a small number of vision neurons, causing poor eyesight. Ants have a larger number of neurons that control learning and olfactory information through its antennae. The antennae help an ant find food, locate other ants, and communicate. A human brain is one million times larger than an ant’s central nervous system.

 

Read more: Do Ants have Brains

 

Animals, including ants, have specialized sensory neurons that detect and alert them to harmful stimuli, such as temperature, pressure, or chemical changes. These pain-sensing neurons are called nociceptors. They convert stimuli into electrical signals that are relayed to the brain and allow the animal to react. Reactions include rapid withdrawal or escape from damaging stimuli. We, as humans, can feel pain and react since we have a complex nervous system, while an ant’s nervous system is modest. 

Two ants on a violet
Two ants on a violet, Credit: Wikimedia/Amanda Blom Photography

Scientific study on insect pain

Scientists disagree on whether an ant can feel pain, but studies are opening new doors into understanding. Two scientists from the University of Sydney, Associate Professor Greg Neely and Dr. Thang Khuong, completed research on pain in fruit flies (Family: Drosophilidae). Their eye-opening study proved that insects experience chronic pain after an initial injury has healed.

 

The researchers damaged a nerve in one leg of a fruit fly and gave it enough time to heal. They determined that the fly’s other legs were now hypersensitive. “After the animal is hurt once badly, they are hypersensitive and try to protect themselves for the rest of their lives,” said Associate Professor Neely. “It’s almost like an anxiety-like state, where once they’ve been injured, they want to make sure nothing else bad happens.”

 

Neely explained further, “The fly is receiving ‘pain’ messages from its body that then go through sensory neurons to the ventral nerve cord, the fly’s version of our spinal cord

 

While their research was not completed on ants, we can compare an ant to a fruit fly. They are both invertebrates and insects. An ant’s brain has 250,000 neurons and a fruit fly has 200,000 brain neurons. As scientists explore the world of insects with new technology, we will have a more detailed answer as to whether they feel pain or just sense a danger to their survival.

Larvae (plural of larva): stage in the development of many animals, occurring after birth or hatching and before the adult form is reached

 

Thorax: the area of the body between the neck and the gut region

 

Ganglia (plural of ganglion): clusters of neurons found throughout the body

 

Olfactory: relating to the sense of smell

 

Antennae (plural of antenna): paired appendages used for sensing in arthropods

 

Sensory: relating to or using your senses of sight, hearing, smell, taste, or touch

 

Neuron: a cell which is part of the nervous system. Neurons send messages to and from the brain.

 

Stimuli (plural of stimulus): anything that can trigger a physical or behavioral change

 

Nociceptor: a sensory receptor for painful stimuli

 

Hypersensitive: excessively or abnormally sensitive

 

Anxiety: abnormal and overwhelming sense of apprehension and fear 

 

Ventral: situated on or toward the lower, abdominal, or front part of the body

 

Spinal cord: a column of nerves that runs from the brain down the back inside the bones of the spine

 

Readability: 62.7

 

Flesch Kincaid Grade Level: 8.1

Blake, Elissa. Thwack! Insects Feel Chronic Pain After Injury. July 11, 2019. https://www.sydney.edu.au/news-opinion/news/2019/07/11/thwack–insects-feel-chronic-pain-after-injury.html

 

Koumoundouros, Tessa. There’s Growing Evidence That Insects Feel Pain, Just Like Us. July 10, 2022.
https://www.sciencealert.com/insects-probably-do-feel-pain-similar-to-how-we-do-scientists-argue

 

Adamo, Shelley. Do Insects Feel Pain? September 2, 2019. https://esc-sec.ca/2019/09/02/do-insects-feel-pain/

 

Gorvett, Zaria. Why Insects Are More Sensitive Than They Seem. November 28, 2021. https://www.bbc.com/future/article/20211126-why-insects-are-more-sensitive-than-they-seem

 

Georgiou, Aristos. Insects May Be Able to Feel Pain, Study Suggests. July 5, 2022. https://www.newsweek.com/insects-may-able-feel-pain-study-suggests-1721418

 

Ant Brain Complexity at a Cellular Level Revealed for the First Time Using Single Cell Technology. June 16, 2022. https://phys.org/news/2022-06-ant-brain-complexity-cellular-revealed.html

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