The Gene Scanner in Probably Stolen shows the allele colours of your animals, so you can tell which rats are worth breeding before you spend food and cage space on their litters. Green marks a favourable value and red an unfavourable one: a low Hunger Rate shows green, a high one red. A pup inherits one allele from each parent, so keep parents whose values are both good.
At a glance
| Used for | Showing animal allele colours |
|---|---|
| Green | A favourable value, e.g. low Hunger Rate |
| Red | An unfavourable value, e.g. high Hunger Rate |
| Inheritance | One allele from each parent |
| Serums | Temporary boosts, not inherited |
What the Gene Scanner does
The scanner is a shop tool tied to animal farming. Toggle it while interacting with an animal and it displays that animal's alleles as coloured values. It does not change the animal; it only tells you what you are working with. Pair it with the rat guide for housing, feeding and cage repairs.
Green versus red
Colours follow the direction that helps you, not the raw number. For Hunger Rate, lower is better, so a low value shows green and a high value shows red. Community guides note the developer patched this colour logic, so older videos that show the opposite may predate the fix.
How pups inherit traits
Each trait has two alleles. A pup gets one from each parent, chosen from that parent's pair. A parent with one green and one red allele can pass on either, so the safest breeders carry two green values for the traits you care about.
Which traits to check first
For meat stock, community guides suggest this order:
| Priority | Trait | Why it matters |
|---|---|---|
| 1 | Growth rate | Faster to slaughter weight |
| 2 | Hunger rate | Less food per rat |
| 3 | Immunity | Fewer sick animals |
| 4 | Fertility | More frequent litters |
| 5 | Litter size | More pups per litter |
Serums do not breed true
Immunity Serum raises immunity and Steroid Serum speeds growth while lowering immunity. These are temporary boosts on the animal you treat; guides agree offspring do not inherit them. Scan before you dose so you judge the real genes.
A simple selection routine
- Scan every new rat and note its growth and hunger alleles.
- Keep one male and one female with the most green values.
- Sell or butcher animals carrying two red alleles in a key trait.
- Rescan each litter and replace parents when a pup beats them.
What is not confirmed
The developer has not published full documentation for the rat system. What the letters and small numbers next to each allele mean beyond the colour is not spelled out, so treat exact values in community tables as estimates.
Sources and further reading
- Official Steam store page
- Developer patch notes (Gene Scanner colour fix)
- Rat breeding, growth and genetics (community)
- Rat farming guide (community)