--- title: 'Dewey: a connectome-driven fruit fly living in your macOS menu bar' canonical: https://0110.be/posts/Dewey%3A_a_connectome-driven_fruit_fly_living_in_your_macOS_menu_bar markdown_url: https://0110.be/posts/Dewey%3A_a_connectome-driven_fruit_fly_living_in_your_macOS_menu_bar.md id: 587 published_at: '2026-10-10T00:00:00Z' updated_at: '2026-10-10T23:28:32Z' author: Joren tags: - name: Code markdown_url: https://0110.be/tags/Code.md - name: Projecten markdown_url: https://0110.be/tags/Projecten.md - name: UGent markdown_url: https://0110.be/tags/UGent.md --- # Dewey: a connectome-driven fruit fly living in your macOS menu bar Recently, researchers released the [complete connectome of a male fruit fly](https://male-cns.janelia.org/): a map of the neural connections in its brain and nerve cord. The [accompanying paper](https://www.cell.com/cell/fulltext/S0092-8674(26)00942-6) describes this work. I have connected a simplified version of part of that connectome to a 3D model of a fly and now have a fly zooming around on my mac. It flies around the desktop, lands on windows, and is scared of the mouse cursor.
I have called it Dewey. That way it should at least like part of its own name: *[Drosophila](https://en.wikipedia.org/wiki/Drosophila)* means “dew-loving”. I am not sure what Dewey feels or thinks about being stuck in the matrix. To make it less lonely, I have built in an option to at least add a few friends. There are deeper philosophical questions to raise about simulating neural circuits. Is it purely reflexive? At what point might there be something more? These questions become especially worrying if we start doing this with a social species such as a bee, or eventually animals with more complex nervous systems. Imagining the [*Umwelt*](https://edyong.me/an-immense-world) of an animal, is difficult enough in the real world. What an Umwelt would look like in a virtual world breaks my brain. Seeing Dewey fly around is nice. The process of creating Dewey, much less so. I prompted a recent LLM to connect the brains to a body and essentially guided the process until Dewey appeared. A mere year ago, getting such a result would have taken me days, if not weeks. I would also have had to learn a lot more about neural activation patterns and the intricacies of rendering and animating a 3D fly. Now, I am much less motivated to do that deep dive, since the result is already there. The fly flies. The cursor scares it. I can add friends. There is still plenty to learn, but the immediate reason to learn it has disappeared. If a reward without much effort is within reach, it takes a discipline to go the extra mile, discipline I seem to lack. I have gained a desktop fly and missed out on part of the process of making one. Anyway, check out the [paper](https://www.cell.com/cell/fulltext/S0092-8674(26)00942-6), [run Dewey on your Mac](https://github.com/JorenSix/Dewey/releases/latest), or have a look at the [code on GitHub](https://github.com/JorenSix/Dewey).