Tiny Creatures

What am I looking at?

This is a real-time evolution simulation. Dozens of tiny creatures live in a 2400×1800 pixel world divided into biomes. They eat, reproduce, and die — and over generations, their neural network brains evolve through natural selection and mutation. All behavior is learned, not programmed. No creature is told what food is, what a predator is, or how to survive. They figure it out — or go extinct.

What are the creatures doing?

Each creature has a neural network brain with 44 inputs, 24 hidden neurons, and 8 outputs (1,280 learned parameters). The brain controls everything: where to move, how fast, when to bite, when to reproduce, and what signals to broadcast.

Crucially, creatures have no hardcoded instincts. They don't know what food is, what other creatures are, or what danger looks like. They perceive the 5 nearest entities as raw sensory data — direction, distance, size, and color — and must evolve to make sense of it all. Over generations, creatures that stumble into useful behaviors (like moving toward food-colored things and biting) survive and pass on their brain weights.

What do their appearances mean?

Every visual trait is gene-driven and heritable:

• Body color — hue, saturation, and lightness are each separate genes
• Body size — ranges from 8 to 18 pixel radius; bigger creatures drain more energy
• Legs — 0, 2, 4, or 6 legs; more legs = faster scuttling gait
• Antennae — decorative gene (present/absent)
• Tail — affects swimming animation for legless creatures
• Spots & stripes — pattern genes (present/absent each)
• Eye size, mouth size, blush — affect their cute little faces
• Elongation — stretches the body into a worm/snake shape

How does diet work?

A creature's diet is controlled by its dietType gene (0–1):

• Herbivore dietType < 0.3 — gets full nutrition from plants, barely digests meat (10% efficiency)
• Omnivore dietType 0.3–0.7 — decent at both plants (70%) and meat (60%)
• Carnivore dietType > 0.7 — full nutrition from meat, struggles with plants (30%)

Creatures with high bite strength can attack other creatures — but only if their neural network learns to do so. Attacking costs 4 energy. Whether carnivores learn to hunt, and who they target, is entirely emergent behavior.

What foods exist?

Each biome grows its own food types. Soft foods (berries, clover, flowers) can be eaten by anyone. Harder foods require stronger jaws:

• Meadow — berries (42 energy) and cloverbuds (25)
• Flowerfield — flowers (18), nectardrops (15), berries
• Forest — mushrooms (55, need bite 0.3), acorns (70, need bite 0.5)
• Swamp — mossballs (35), mushrooms
• Rocky — seeds (80, need bite 0.6), crystalberries (60, need bite 0.4)
• Pond — waterlilies (20), tadpole eggs (30, need bite 0.2)
• Meat — 3 pieces dropped when a creature dies (7 energy each), disappears after 10 seconds

How does energy work?

Creatures start with 160–200 energy. They constantly burn energy just by existing (0.003/tick), plus extra for moving fast and being large. Crowded areas and overpopulation drain even more energy — the ecosystem has a natural carrying capacity. When energy hits zero, the creature dies — you'll see them wobble, squish flat with a cute splat, then fade away, leaving behind meat.

Snow slows creatures down by up to 20% and reduces food growth. Rain boosts food regrowth in most biomes.

How does reproduction work?

Reproduction isn't automatic — a creature's neural network must decide to reproduce (repro_intent output > 0.5), and it must have energy above 55. Social creatures (sociability gene > 0.4) look for a nearby mate and combine genes — each gene has a 50/50 chance of coming from either parent. Less social creatures reproduce asexually by cloning their genes.

Either way, each gene has an 8% chance of mutating by up to ±0.3. The neural network brain is also cloned and mutated. The parent spends about 24 energy; the child starts with about 31. There's a cooldown of 2–3 seconds between births.

What are the biomes?

The world is divided into six biomes using layered noise patterns:

• Meadow — open grassland, the most common biome
• Flowerfield — colorful flower patches
• Forest — darker, tree-dotted areas with richer food
• Swamp — murky wetland zones
• Rocky — stone terrain with high-energy but hard-to-eat foods
• Pond — water areas with lilies and eggs

What are the tiny floating things attacking creatures?

Those are germs — they appear when the population exceeds 150 as a natural population control. Germs drain energy from their host and can spread to nearby creatures. A creature's curiosity gene doubles as its immune system — higher curiosity means better chance of fighting off infection.

What's actually evolving?

Both genes and brains. Over generations, natural selection shapes two things simultaneously:

• Genes — body size, speed, diet, bite strength, sense range, sociability, and all visual traits
• Neural network weights — the 1,280 parameters that control all decision-making

Because creatures start with random brains, early generations are chaotic — they wander aimlessly and most starve. But creatures that accidentally move toward food and bite it survive longer, reproduce more, and pass on their brain weights. Common emergent outcomes include:

• Creatures learning to approach food-colored entities and bite them
• Herbivores dominating early (plant food is abundant and easy)
• Carnivores sometimes evolving to hunt — or going extinct entirely
• Creatures learning to avoid larger, aggressive neighbors
• Social signaling emerging through the communication channel
• Smaller creatures surviving famines (they burn less energy)

The Generation counter in the stats panel shows how many reproduction cycles the oldest lineage has gone through.

How does the brain work?

Each creature's neural network has three layers: 44 inputs → 24 hidden neurons → 8 outputs.

Inputs (what they sense):

• 5 entity slots — the 5 nearest things (food or creatures), each described by: direction (dx, dy), proximity, size, and color hue. The creature doesn't know what anything is — just where it is and what it looks like.
• Self-state — own energy level, size, speed, diet type, age, reproductive readiness, and whether it was recently hurt
• Communication — strongest nearby signal (strength, value, direction from sender)
• Wall proximity — distance to the 4 world boundaries (left, right, top, bottom)
• Memory — 2 recurrent values fed back from the previous tick, giving creatures a primitive short-term memory
• Kin awareness — whether the nearest creature is a parent, child, or sibling. No hard-coded protection; the brain decides what to do with this information

Outputs (what they decide):

• steer_x, steer_y — movement direction
• speed_mod — how fast to move (0–100% of max speed)
• bite_intent — attempt to eat/attack the nearest entity
• repro_intent — attempt to reproduce
• signal_emit — broadcast a signal that nearby creatures can sense
• recur_0, recur_1 — memory values carried to the next tick

What can I do? (God Powers)

• Observe — click a creature to see its stats, genes, and neural network
• Feed — drop 8 berries at the cursor
• Nurture — give 40 energy to the nearest creature
• Wall — drag to draw barriers that creatures bounce off
• Zap — instantly kill creatures in a 50px radius
• Rain — spawn 20 random food items at the cursor
• Love — force two nearby creatures to mate
• Mutate — create a mutagen zone (60px radius, 10 seconds) that increases mutation rates for creatures passing through

Camera & Controls

• Scroll wheel — zoom in/out
• Arrow keys — pan the camera
• H key — reset camera to home position
• Click minimap (bottom-left) — jump to that location
• Auto Camera — follows interesting clusters of creatures automatically
• Speed buttons — 1× to 10× simulation speed

Why did everything die?

Mass extinction events can happen! Common causes: creatures failing to learn to eat in early generations, food depletion from overpopulation, a germ epidemic above 150 creatures, or harsh weather reducing food supply.

An extinction safety net prevents total die-offs: if population drops below 10 (early generations) or below 5 (later generations), the best survivors are cloned with slight mutations — preserving evolutionary progress rather than starting over. When population is critically low, creatures also burn less energy, giving them more time to find food and recover.

Tiny Creatures is a generative art & science toy.
No two simulations are alike. Enjoy watching life find a way.