Can Ants Become Dependent on Morphine?

By Paul Gaita 09/29/16

A new study examined whether a social insect like an ant could form a drug dependency. 

Can Ants Become Dependent on Morphine?

A recent study may reveal a new model for understanding how opioids affect the human brain by testing a unique subject: ants. Researchers from the University of Scranton in Pennsylvania sought to better understand the “down-cascading” effect of addiction by examining its impact on communities, from social circles to neighborhoods.

Ants were chosen over more traditional test subjects like rats due to the complex and interdependent nature of their societal relationships. The results, published in the Journal of Experimental Biology, may provide fresh insight into human behavior and addiction.

To conduct the test, the researchers established two groups of ants, each of which was presented with a bowl of sugar water, which was lowered in concentration over a period of four days. However, one group’s bowl also contained morphine, which remained at a consistent level throughout the test.

As the researchers discovered, the ants that received the bowl containing only sugar and water lost interest in the solution by the end of the test period, while the ants that received the bowl with morphine continued to return to feed at the bowl, even after the sugar and water had dissipated. 

To further determine the depth of the addiction, the scientists presented the morphine group and a control group of new ants with two bowls: one that contained morphine, and another with the sugar-water mix. Sixty-five percent of the morphine group chose the bowl with the drug, while the majority of the second group chose the bowl of sugar water.

Samples from the brains of ants from both groups revealed significantly higher levels of dopamine in the morphine group than in the sugar-water control group.

“We’ve proven ... that the neurochemical pathways [in ants] are similar to mammals,” said Marc Seid, the study’s senior author. “What’s most exciting to me is the next step. We can addict individual ants and see how that affects the ants’ social network, which is somewhat like humans."

While the test may be regarded as a landmark in regard to its subjects—the authors believe this is the first test to show that a social insect like an ant can form a drug dependency—the study has its detractors. “The results are very interesting, but perhaps not unusual given the deep history of animals using plant-derived compounds, including alkaloids like caffeine and morphine,” said Boston University biologist James Traniello.

Traniello cited a study which showed that honeybees exhibit improved short-term memory when they ingest plant nectar containing caffeine. And as University of Arizona neuroscientist Wulfila Gronenberg noted, the findings don’t prove that the ants developed a genuine dependency on morphine. “It is possible that the ants in the study got addicted to morphine, but the authors don’t show evidence for addiction,” said Gronenberg.

The researchers plan to follow up on their study by charting specific neurons activated by dopamine in the brains of ants, and are working with a mathematician to create models of ant social networks.

“We can have a society in a microcosm,” said Seid. “We can dissect pieces of these networks and manipulate individuals to get a better idea of addiction’s down-cascading effects.”  

Please read our comment policy. - The Fix

Paul Gaita lives in Los Angeles. He has contributed to the Los Angeles Times, Variety, LA Weekly, and The Los Angeles Beat, among many other publications and websites.