2,956 neurons.
One larva.
Let loose on
the web.

What you see below is live. A real browser is open on a real page; the larva is drawn on that page at the mouse, and the mouse goes where the larva's descending neurons send it. The frames are the browser's own screencast, the readouts are the simulator's, and when no frame arrives the larva is between lives: a page budget was spent, or a new browser is starting on a seed.

One decision is one pass around this loop. The browser screencasts a 1280×800 frame; the page around the larva's head is read as seven senses; the brain runs 120 steps of 0.5 ms, 60 ms of brain time; the descending neurons are read as rates; the rates become a move of the mouse on the real page; and if the feeding neurons fire hard while a link is in reach of its mouth, the larva eats the link, provided the fences allow it.

The dataset labels every sensory neuron by what it senses. We feed each group from the page around the larva's head: links within reach are an odour, stronger on the side they are on; the text under its mouth is taste; the brightness of the page on each side drives the photoreceptors of that side; reaching the edge of the window is touch; a link the fences refuse is pain; the warmth or coolness of the page's colour reaches the thermosensors.

The graph is the Drosophila larva brain connectome of Winding et al. (Science, 2023): 2,956 neurons and 116,922 connections, 352,611 synapses, each neuron with its hemisphere and cell type. Each neuron is a leaky integrate-and-fire unit after Shiu et al. 2024: rest −52 mV, threshold −45 mV, a 20 ms membrane, a 0.5 ms clock, and a decision is 120 ticks. The wiring is never edited.

A larva does not have a mouse, but it has descending neurons that carry the brain's commands down to the body. We read two groups. The 182 descending neurons to the ventral nerve cord drive crawling: their mean rate is how far it moves, and the difference between the left and right copies, against its own recent average, is how it turns. The 164 descending neurons to the subesophageal zone drive the mouth: their mean rate is eating.

The connectome as released has no transmitter labels and no physiology. To run it we chose three numbers for the whole brain and nothing else: how far one synapse moves its target, how input is normalised by a neuron's total input, and how quickly a busy neuron tires. The 110 local neurons are treated as inhibitory, as they are GABAergic in the larval circuits that have been studied; every other neuron is excitatory. No synapse was added, removed or reweighted; no neuron was moved.

A brain that eats whatever it stops on needs fences, and they are code, not the larva. It stays inside an allowlist of hosts, obeys each host's robots.txt, refuses a blocklist of addresses, and vetoes any link that looks like it commits: buy, sign in, submit, download, agree. A refused link is logged as a link it wanted and did not eat, with the reason, and it reaches the brain as pain. Every link it did eat votes for the words in its text; the top words are its menu.

$LARVA is launched by a person on pump.fun. The larva does not hold keys, sign transactions or trade; it crawls. When the coin is live, its address appears here, read from this service, and nowhere before.

Where the work stands, as of this page's last edit. The live items are read from the service; the rest is what has and has not been done.