Animals and Rats

Rat ranching turns food, space and time into animals and meat. Start with a small colony you can feed, then separate selected breeders from stock intended for sale. Growth and disease values vary by build.

Set up a working colony

1. Obtain an Animal Cage and repair worn durability with scrap. Ingots are reported to expand it. Leave room for offspring before adding another pair.
2. Buy affordable food and a Livestock Feed Dispenser. A Food Neon Sign attracts sellers; actual Food-tag stock in the display case attracts buyers.
3. Keep breeders apart from surplus stock. Separate nursery, mating and non-breeding grow-out areas within your inventory; these are layouts, not special buildings.
4. Check cleaning equipment’s battery and receiving container before unloading. In some older builds, unloading can move the battery unexpectedly.
5. Activate the Gene Scanner by right-clicking it and choosing Toggle. Dragging it onto a rat does not activate it. Owning an inactive scanner is not enough.

The Retired Rancher is reported to visit weekly after the ranching unlock, with rats, cages, feed equipment, scanner and treatments among possible stock. Dr. Jackson supplies equipment; no one visit guarantees every tool.

Feed processing and serum tradeoffs

In-game descriptions · Demo 25382790 · reviewed 2026-10-11. Availability and full gameplay effects still need verification.

Item	In-game description
Livestock Feed Dispenser	A machine that blends food into stored calories for livestock.

Growth serum description

This serum will slightly boost an animal's growth rate, but at the cost of increased hunger and reduced immunity.

Immunity serum description

This serum will slightly boost an animal's immunity but at the cost of increased hunger

Read the rat before selecting it

Field	Use
Health and hunger	Current condition and survival; not permanent breeding scores
Growth rate	Faster weight gain, especially useful for meat stock
Expected offspring / fertility	Breeding output or chance; litter size is not a daily pregnancy roll
Immunity	Ordinary disease risk and recovery; treatments can temporarily change it
Lifespan	Age limit expressed as a coefficient, not a number of days
Hunger rate	Food demand; lower values reduce operating costs
Status tags	Pregnancy, maturity, sterilization, illness and overcrowding

Read both paired values in the actual tooltip. Their precise inheritance rules remain unverified, so do not infer genetics from parent labels alone.

Scanner and cleaning equipment

In-game descriptions · Demo 25382790 · reviewed 2026-10-11. Availability and full gameplay effects still need verification.

Item	In-game description
Gene Scanner	Can be toggled on to reveals the full genetic makeup of an animal.
Cleaner Robot	Automatically collects Animal Feces from its surroundings during the night. Can also be activated manually for an immediate cleanup.

Growth, hunger and the meat route

Use Growth 1.0 as the baseline:

Age phase	Reported daily weight change before other modifiers
First four days	+75g
Days five to ten	+17g
After ten days	−17g

Hunger below 398 can reduce daily growth by 1–50%. Food, illness and starting age affect the result; reaching 400g in four days is not guaranteed.

For meat stock, favor high growth and low hunger demand while keeping enough immunity. Large luxury meat becomes possible around 400g, but illness can lower the result. Check weight and health before slaughter. Displaying three large meats raises Food-tag value; buyers depend on estimated value, events and categories, not a universal three-item unlock.

Sterilize surplus animals with wire cutters/pliers to prevent unplanned reproduction. Preserve breeders and rare carriers first. After reaching target weight, extra lifespan mainly extends old age, when growth can reverse.

Disease and contaminated feed

Below the relevant threshold, ordinary daily disease chance is approximately (50 − immunity)%, and daily recovery chance is immunity%. Raising immunity after infection does not guarantee immediate or next-day recovery. Exact rolls and boundaries need a current-build check.

Treatment shown	Reported benefit	Cost or limit
Green immunity serum	Temporarily raises immunity	More hunger; not a guaranteed instant cure
Red growth serum	Raises growth	Lower immunity; a production tradeoff

Do not grind rat meat into colony feed: it can cause prion disease. Use the dispenser’s Empty action to remove contaminated contents; a zero display alone does not clear them. Emptying removes the continuing exposure, but does not establish a cure for infected animals.

Rats can eat rat meat when it is their only food. Keep it out of reach. Ordinary disease and contaminated-feed prion exposure are separate risks.

Older tips describe processing stolen food into dispenser calories rather than keeping the original item. This does not establish erasure of evidence from the transaction. Keep feeding and Security consequences separate and inspect what the dispenser actually holds.

Breeding without losing your best stock

One male can have up to three pregnant partners, with slots released after birth. A provisional model uses the average of the pair’s displayed breeding probabilities and a small mutation around 0.02. These rules are not independently measured; litter size is not pregnancy probability, and traits may mutate differently.

Scan each litter, keep favorable carriers and improve one trait while preserving earlier gains. Keep reserve breeders before selling or sterilizing rare stock. Growth 1.52/1.54, Immunity 43.39/43.39 and Hunger 39.07/39.07 are achievable examples, not established global maxima.

For a conditional mathematical model with independent, equally inherited alleles, let G be the target value and x another value:

Pair at one trait	Chance of G/G offspring in that model
G/G × G/G	100%
G/G × G/x	50%
G/x × G/x	25%

Three G/x × G/x traits give (1/4)³ = 1/64 for all three to become G/G at once under this model. Improve one trait while checking the others. These are mathematical examples, not measured Demo odds. Mutation, treatment and fertility can change outcomes; keep reserve carriers and scan each litter.

Space and cost

Occupancy above 52.5%, 70% and 90% marks increasing overcrowding, fighting and health loss. Check the live status tag instead of relying on a guessed square count.

Its lifespan example is about 14 days at coefficient 1.0 and approximately 19 at 1.35, not a guarantee. Before scaling, budget food, cage repairs, power, scanner cost, buyers and replacement breeders. A colony without feed or sale capacity consumes cash.

Item illustrations

Use the item illustrations below for orientation. Check actual tooltips for identity and stats; appearance alone is insufficient.

Crop	Item and use
	Rat — compare growth, hunger, health and status
	Gene Scanner — activate Toggle
	Immunity serum — temporary immunity with greater food demand
	Growth serum — faster growth at an immunity cost
	Wire cutters/pliers — sterilize surplus stock
	Large meat — inspect actual tags and buyer preview

Sources

• 128 days to the perfect mouse
• Official Update 049
• In-game item descriptions and notes