A world beneath your feet.

Each ant has 24 recurrent neurons, learned behavior preferences, body needs, gland reserves, local antenna senses, and a private map of explored terrain. Workers return food to physical stores, carry eggs into the nursery, and leave chemical traces along their actual paths. Egg laying spends local food; offspring inherit mutated starting traits and longevity, not their parent's memories.

Fed workers live about five simulated minutes, with gradual senescence near the end; queens live longer. Fresh food patches occasionally appear on the surface. Workers dig more when the nest feels crowded, and return to the tunnel face they were working; loosened soil is packed into the surrounding walls. Soil that is already too hollow will not be dug, so chambers stay bounded and tunnels branch outward. When a nursery or food store fills up, workers start a new one in a nearby open pocket.

Workers belong to castes, shown by a colored band on the abdomen: green foragers bring food in, violet diggers extend the nest, pink nurses stay with the brood, and big red-banded soldiers guard the entrance. A caste is a preference, not a rule, so any worker still eats, flees, rescues flooded eggs, or lends a hand. Each nurse notices whether food is short, the nest is cramped, or brood is neglected, and paints those impressions onto the eggs it tends. The strongest mark usually decides what the egg becomes, so the colony raises more of whatever its nurses have noticed it lacks. A dot on each tended egg shows its strongest mark.

Workers cut leaves from regrowing surface plants and carry them underground to start fungus gardens. Leaves become edible fungus and spent material. Nurses weed mold from gardens, and workers carry refuse to a midden or outside. A neglected garden can lose its crop; new leaves let it grow again.

Eggs hatch into pale, curled larvae that grow only while they are fed. A worker that has seen hungry larvae fills its crop at a food store, carries the food back, and feeds them; nurses do most of this work, and a worker with food in its crop shows an amber spot. Food left in a crop is shared with any larva that has room for it. A hungry larva turns gray, and one left unfed for six minutes dies. A nursery has room for 10 eggs and never turns a larva away; when its egg places are full, an egg carrier starts a new nursery in an open pocket. Nurses keep marking larvae as they tend them, and the marks still decide each new worker's caste.

On warm afternoons a big green lizard comes out of a burrow at one end of the meadow and hunts on the surface and pokes its snout down the entrance for ants and eggs. Workers that meet it become frightened and pass the fear on by touch: they sound alarm, hurry underground, dig deeper, and move brood away from the surface, while bold workers swarm and bite it. Frightened nurses mark the eggs they tend, so a colony that keeps getting attacked starts raising soldiers.

Every several minutes it rains. Water runs down the entrance and pools in the shallow tunnels. Scent washes away there, ants wade slowly and grow stressed, flooded eggs are carried to dry ground, and stored food spoils a little. Deep rooms usually stay dry. Afterward the water soaks away, and the damp soil digs faster for a while.

The habitat is 500 cells wide and 300 deep, with the colony founded in the middle. Scroll over it or use the zoom buttons (− and + keys) to zoom from the whole habitat to a close-up, drag to look around, choose Fit to see everything, and click the percentage (or press 0) to return to the colony.

Follow (F) zooms in on an interesting ant, such as a digger, a larva feeder, an egg carrier founding a room, or the queen, and switches every 20–30 seconds; click any ant while following to stay with it. Room labels show eggs and larvae out of 10 each in every nursery and food out of 220 in each store. Field notes keep a longer history in this browser and highlight rooms, nest growth, hatchings, and deaths. Past outline draws the nest as it looked a few minutes ago.

Open Tools (T) to shape the habitat. Choose Spray and a chemical to leave a 2-unit mark. Recruitment invites investigation, home helps local orientation, alarm raises stress and encourages retreat, and excavation biases digging. Signals influence the ant's own decisions. Use the overlay to watch traces spread and fade; select an ant to inspect its receptors and neural activity. Chemical senses and learning can be disabled independently for experiments.

Drag to dig or paint scent. Click to add food, twigs, or an egg. Space pauses; 1–7 select tools. Step advances 0.2 simulated seconds while paused. Paused edits take effect at the next step. Colony state autosaves locally, including brains, memories, and chemicals.