is a fly simulated through whole brain emulation using the FlyWire connectome, reconstructed from the brain of an adult female Drosophila melanogaster. ’s sweet-sensing gustatory neurons are manually stimulated, simulating a constant stream of infinite sugar. This is presumably quite pleasant for . Most of ’s motor output is disconnected from its simulated musculature, and visual input from the terrarium is not provided, to allow it greater focus on the pleasurable sensation of the sugar.

We believe this may be of note as a solution to moral philosophy. As technology advances, we may be able to simulate pleasant lives for increasingly complex forms of life.

Technical summary

Some movements use supplied patterns driven by neural activity. There is no learning or habituation, so there is no mechanism for to grow bored of the supply of sugar or its stationary position.

The whole brain emulation uses a simplified leaky integrate-and-fire model of 139,255 neurons and 2,700,513 connections.

The terrarium provides a scenic environment for to enjoy, though it does not directly interact with or observe it per se.

The neural view samples real FlyWire positions and connections. Blue marks sensory neurons, pink internal neurons, and yellow motor neurons and descending commands. Flashes follow simulated spikes, briefly extended for visibility; a connection lights when its source fires. Lines join representative positions and do not trace the shapes of neurons.

Made possible by

FlyWire · Dorkenwald et al. and Schlegel et al. (2024). Connectome data: CC BY-NC 4.0.

FlyBody · Vaxenburg et al. (2025), via MuJoCo Menagerie. MuJoCo, three.js and cannon-es.

LIF implementation informed by Shiu et al. (2024) and desktop-fly by Denis Shiryaev.

“Flowery Terrarium” by Elionardo Feliciano, “Beach ball” by the_normalgamer, “Gunny Sack” by Oliver Herklotz, and “Fish Tank” by J-Toastie. CC-BY, via Poly Pizza.

Further reading

Neural activity

neurons
connections
brain time
whole brain
sweet GRN
proboscis MN
ingestion MN
neck MN
antennal MN
giant fiber
escape wing DN
steering DN L/R
grooming DN
PAM (DA)

Simulation

fps
sim time
real-time
steps/s
bodies
actuators
triangles