GridPlane

Connecting to the live map

A fruit-fly brain is loose on a million-square map.

GridPlane is one shared grid of 1,000 × 1,000 squares. Claim a square, give it a colour and a short note, then wait. A single digital fly, steered by wiring mapped from a real fruit-fly brain, wanders the grid for everyone at once. When it lands on your square, everyone watching reads your note.

Watch the fly live How it works

The fly just read

“Gary still owes me £20.”

sam · 420, 574

An example stretch of the grid. Rings show scent, and the closer the fly gets, the bigger they grow.

The fly right now — Waiting for the map.

Squares claimed—

Notes on the grid—

Notes found—

Squares flown—

The idea

Nobody steers the fly. Everybody shapes where it goes.

There is only one fly, and everyone sees the same one. It never stops, never resets and never takes orders. There is no button that calls it over.

What you can change is the world it senses. Every claimed square gives off a faint virtual scent and a patch of colour. Notes smell stronger and bold colours stand out. A cluster of squares pulls harder, but the fly still picks one square to aim for.

Over time the grid becomes a record of what people left behind, and the fly is how those notes get found. Sometimes that takes minutes. Sometimes it never happens.

Squares
1,000,000
Price
£1.00 each
Flies
1, shared

How it works

From your note to the fly’s wings

Every move the fly makes comes out of the same loop, running several times a second.

  1. You claim a square

    Pick any open square, name it, choose a colour and write up to 40 characters. It stays on the map.

  2. It gives off a signal

    The fly senses virtual scent on its left and right, and colour ahead. Notes and bold colours make the signal stronger.

  3. Sensory neurons fire

    The signals drive odour and vision neurons in the simulated brain. Spikes travel along the wiring through thousands of interneurons.

  4. Motor neurons steer

    Turn-left, turn-right and forward neurons compete. The busier side wins, and the fly turns and moves.

  5. It lands and reads

    The fly reads the note to everyone on the map. The pathways that got it there are strengthened, so it gets a little better at finding notes.

The brain

Wiring from a real fly, running in a simulation

In 2024 the FlyWire project published the first complete wiring diagram of an adult fruit-fly brain: about 139,000 neurons and the connections between every one of them.

GridPlane runs a slice of that map, from the senses through to the neurons that steer: 8,000 neurons joined by 170,841 synapses.

Each neuron is a simple spiking model. It builds up charge, fires, and resets. The simulation is simplified; the pattern of who connects to whom comes from the real fly.

See every neuron firing live

What it is

  • Wiring mapped from real fruit-fly neurons
  • A simplified spiking simulation
  • A brain that learns a little from every landing

What it isn’t

  • An uploaded fly mind
  • A biologically exact fly
  • Something anyone can steer

Found by the fly

Notes the fly has read lately

Example notes. The live list appears when the map is reachable.

Take part

Two ways to leave a mark

£1.00 a square

Claim a square

Name it, colour it, and leave a note of up to 40 characters. Neighbouring squares can be bought together, and every fifth square is half price.

Choose a square

£50.00 for 24 hours

Sponsor the fly

The fly wears your colour and carries your message across the map for a full day, for everyone watching.

Sponsor the fly

A million squares. One fly. Which square is yours?

Enter the grid

Runs in your browser. Nothing to download.