Fruit Flies Are Smarter Than You Think: Play, Genes and Flying Robots

Fruit flies are one of the most studied organisms in biology. They have contributed to research on genetics, aging, neuroscience and behavior for over a century. Recent studies have produced findings that surprised even the scientists involved, and they change how we should think about these small insects.

Fruit flies can learn to play

In 2025, researchers at the Rowland Institute at Harvard published a study in Current Biology showing that Drosophila melanogaster will interact with small balls again and again, even though there is no food or other obvious reward involved. Over repeated sessions the flies learned to prefer balls that stayed still, and they performed an acrobatic move the team called the "ball walk".

The researchers describe this as play-like behavior. It is not the first example in insects: in 2022, a team at Queen Mary University of London showed that bumblebees roll small balls without getting any reward. Together, these studies suggest that play may be more common among insects than anyone expected. Whether fruit flies experience something like enjoyment is still an open question, but the behavior itself is striking.

A single gene can transfer behavior between species

A 2025 study published in Science by researchers at NICT and Nagoya University in Japan showed that changing a single gene was enough to give one fruit fly species a courtship behavior from another. Males of Drosophila subobscura offer the female a gift of regurgitated food during courtship, something Drosophila melanogaster males never do. By switching on the sex-determining gene fruitless in a specific group of brain cells, the researchers made melanogaster males start offering food gifts too.

This finding has implications far beyond fruit flies. It suggests that new, species-specific behaviors can arise from small changes in how existing brain circuits are wired, rather than requiring broad genetic differences across the genome. For biologists studying how new behaviors evolve, this is a significant result.

Fruit flies as a model for tiny flying robots

Fruit fly flight is also a source of ideas for engineers. In 2024, researchers published a study in Nature that used machine learning to work out how the tiny hinge at the base of a fly's wing controls each wingbeat. Engineers working on flapping-wing micro drones study the same system, because flies combine stability and agility in a way that small robots cannot match yet. A fly can even keep flying after damaging a wing, something researchers hope to copy in drones that do not crash after a small failure.

What this means for ant keepers

None of this changes how you breed fruit flies. Drosophila melanogaster and Drosophila hydei remain the two reliable flightless feeder species, and the DIY medium recipe works just as well today as it did before these studies were published. But it is a good reminder that the small fly crawling around your ant enclosure is one of the most scientifically complex and interesting organisms on the planet.

If you want to start breeding your own fruit flies, our DIY fruit fly guide explains the setup step by step and includes our breeding video. Not sure which species to pick? Read melanogaster vs hydei.

Need flies to get started? Our Large Fruit Flies are ready-to-use Drosophila hydei cultures, and the Fruit Fly Culture Set has everything you need to start your own cultures.

Sources

• Iwasaki, K., Kawano, S., Cassod, A., Neuhauser, C. and Rayshubskiy, A., 2025. Drosophila learn to prefer immobile spherical objects through repeated physical interaction. Current Biology. Summary: Harvard Brain Science Initiative.

• Dona, H.S.G., Solvi, C., Kowalewska, A., Mäkelä, K., MaBouDi, H. and Chittka, L., 2022. Do bumble bees play? Animal Behaviour.

• Hara, Y., Yamamoto, D. et al., 2025. Published in Science. Summary: NICT press release.

• Melis, J.M., Siwanowicz, I. and Dickinson, M.H., 2024. Machine learning reveals the control mechanics of an insect wing hinge. Nature.