fly swatter + a real fruit fly brain

the fly does not run if distance < r: jump.

it only sees your shadow on the table. how fast that blob grows (η = dA/dt / A) becomes current in LC4 and LPLC2, taken from the MaleCNS v1.0 connectome, stepped by flybrain. DNp01 (giant fiber) bursts → takeoff. yellow freeze is the tell. slap then. wait and it's gone.

weights are frozen. nothing here was trained to play this.

python -m venv .venv
.venv\Scripts\activate
pip install -r requirements.txt
set FLY_DATA=%CD%\fly-data
flybrain download
run.bat
# or: python -m flygame --windowed

python 3.10–3.12 (3.11 here). MaleCNS loads in the background (~260MB). until then you play a loom-threshold stand-in that reads the same shadow numbers.

how to play it (and film it)

mouse moves the hand. RMB / wheel = height. LMB = swat.

watch the log top-right. that's the fly's cells, not a bot.

• freeze (yellow) = LC4/LPLC2 saw looming. that's the hit window
• DNp01 burst = takeoff, you missed
• T real wiring vs shuffled (same degrees, random partners)
• H hide the hand sprite. the shadow stays. that's the experiment
• Esc = credit

tweet this

copy TWEET.txt. clip ~12s: title card → loom → freeze → slap or miss → hit T.

credit

Connectome: MaleCNS v1.0 — HHMI Janelia / University of Cambridge / MRC LMB / Google Research, CC BY 4.0. Cite Berg et al. 2026, Cell.

Simulation: flybrain (MIT).

male-cns.janelia.org · Google Research · neuPrint male-cns:v1.0