Hets explained in plain English 🤔

Explaining Hets in plain English


In the reptile hobby, “Hets” refers to Recessive mutations (such as Albino’s, Clowns, Desert Ghosts etc).
Both parents must carry the gene to produce visual babys.

Note: In reality the heterozygous condition is not exclusive to recessives, as it applies to any situation where two non-alike alleles are present. Pastels and all other single expression inc-dom morphs are heterozygous. [1] However in the hobby, “het” is commonly used when refering to recessive mutations, except in odd examples like HRA.

So if we use Albino as an example (but all recessive gene snakes work the same).

If we have a Visual Albino Male bred to ANYTHING else other than an Albino or anything that is het for Albino, ALL Bbys will be 100% het for Albino because the visual Albino puts his genes into everything he produces.

If we breed a 100% Het to a Normal etc then only half, 50% of the bbys will get some his genes & are called Possible/Poss Hets.

The trouble is with Poss Hets is you don’t know which ones have or don’t have it and can only usually be found out by breeding them.

Although some Hets carry what are called markers where such as Het Pieds for example USUALLY have tram lines at the bottom of their bellies to their cloaca but can’t be relied on 100% so if buying Hets make sure they 100% Hets & from a reputable breeder as theres A LOT of con men out there will say their snake is het when only poss het of even when they know it a normal!:rage:

If we breed a 100% Het x 100% Het because both carry the gene you will get some visual Albinos & everything else is classed as 66% Hets as there’s a better chance of the bbys being Hets than if just bred from 1 100% het but still really a guessing game.

So . . .

Visual x Visual = All Visual Albino Bbys

Visual x 100% Het = 50% Visual Albino & 50% 100% Hets

100% Het x 100% Het = 25% Normal.

50% 100% Hets.

25% Visual Albinos.

(Because you can’t tell the difference in Hets & Normals they all classed as 66% hets)

100% Het x Normal =

50% Normal

50% 100% Hets

(These are classed as Poss Hets)

Hope that helps :thinking:

D & Jo xx

  1. Hets explained in plain English 🤔 - #4 by t_h_wyman ↩︎


Except hets technically refers to a heterogeneous copy of a gene. That means pastel is a het just a visual incomplete dominant instead of recessive. While it’s used commonly for the recessive genes it isn’t only used in reference to recessive heterozygous vs homozygous genes.





Just so.

“Het” is a slang term in the hobby that is derived from the scientifically legitimate term “heterozygous”. The heterozygous condition is not exclusive to recessives, as it applies to any situation where two non-alike alleles are present. So, as Kristin pointed out, Pastels and all other single expression inc-dom morphs are heterozygous. This point is perfectly illustrated by the morph we call Het RedAxanthic which is the heterozygous form of RedAxanthic


My phone autocorrected sorry


No worries, it happens all the time with “science words”. I’m still trying to get my laptop to accept that hypophosphorylation is a real and does not need to be autocorrected


“Low in phosphate” seems easier to use :sweat_smile:… i have no idea if i read Google right, so im likely wrong.


Great content, we just posted a video about that on our YouTube.


Yeh but all I was trying to do was give a simple explanation to it because it’s all that stuff beginners don’t understand which I thought I explained in the post :+1:


I agree… i also feel its important to explain it in a way that beginners will understand that will also educate them so they don’t get the wrong impression and then confused more later on. It certainly was not my intention to discourage your explanation, just add information to it.


No probs, thank you & sorry if had my head up my arse :pray::+1:


I like using punnett squares to explain.

Percentage is the chance that the animal may be carrying one copy of the gene (an allele), or “heterozygous” thus “het”. (Homozygous is the term for 2 copies.)
Each parent has 2 copies of the gene at that spot (the locus), either visual or normal (wild type in science).
Each baby gets 1 copy of the gene from each parent and must have 2 copies of the gene to be a “visual”, with one copy they are “het”, with no copies they are “normal” or “wild type” which you cannot tell from the het when dealing with a recessive trait, usually. No copies doesn’t mean they don’t have any gene there, they have one, just not the “right” one for our purposes.

Albino (visual, 2 copies)= AA
HetAlbino (not visual, 1 copy) = An or 100%het, certain to be het
Normal (not visual, 0 copies) = nn

Possible pairing outcomes:

Visual x Visual is AA x AA =

[AA Albino] [AA Albino]
[AA Albino] [AA Ablino]
so all visual albino

Visual x Normal is AA x nn =

[An hetAlbino] [An hetAlbino]
[An hetAlbino] [An hetAlbino]
so all of the clutch is certain to be het for albino, thus 100% het

Visual x 100% het is AA x An=

[AA Albino] [An hetAlbino]
[AA Albino] [An hetAlbino]
so half of the clutch are visuals and half of the clutch are hets, the hets are certain, thus 100%.

100%het x Normal is An x nn =

[An hetAlbino] [nn Normal]
[An hetAlbino] [nn Normal]
so half are normal with no copy of the albino gene and half are het, but since you can’t tell them apart, they are labeled 50% het because half the clutch may be het, so any offspring has a 50% chance to be a het.

100%het x 100%het is An x An =

[AA Albino] [An hetAlbino]
[An hetAlbino] [nn Normal]
so 1 quarter of the clutch is visual albino, and the other 3 quarters are not. But of those 3, 2 of them may be het, thus 2/3 of the non-visual offspring have a chance to be het, thus 66%het.

Poshet is “possible het” meaning that a visual was in the lineage of the animal somewhere so it may be carrying the gene, but the percentage chance is unknown. Please, don’t pay extra for a poshet, just count yourself lucky if a visual pops up sometime. :grin:

Honest breeders will tell you if they know the percentages, some will tell you if they know there is a chance of the gene so you will know it may be there. Dishonest breeders will claim a chance and then charge more for the “%het” knowing that if it doesn’t prove out they can cover themselves by saying “oh well, guess you didn’t get lucky”. If you have to have the gene, buy a visual, if you trust the breeder, you can take the chance on the 100%het actually being het and pay for it. If none of us ever paid extra for the other percentages, we might be able to reduce the occurrences of dishonest sales.

As a breeder, I never charge for a het percentage less than 100%, and that is when I know, because I made it. I will inform the buyer of any possible genes so they know for their own records, but I can’t, in good conscience, charge for it. I’d like it if that was the industry standard.:person_shrugging:


I LOVE punnet squares!!! I did some crazy one for someone once just for fun… lol

And don’t yell at me that was when I didn’t know better about incomplete dom vs co dom… lol

I am missing the very end of it but it was fun … this one was 2 years ago and I got challenged on a whim.


Yeah, gets unwieldy when you get up there in the gene count or get multiple recessives, but still fun.


Agreed for sure


Many moons ago, for a high school project, I did, by hand, a six gene x six gene square. Took me a couple days with double-checking and all…

These days, you can have the internet make a 5 x 5 in the time it takes to click a button:


So gorgeous, math and science are beautiful :blush:


I still love doing punnett squares just for fun. I’m actually working on a punnett square right now. :rofl:


I think I need this as a Screensaver or background, maybe a t-shirt just to see how many people get it.:grin::rofl::joy:


That’s wild! I’m impressed a high school project went that deep into genetics

If you want I’ll send you all my Drosophila crosses.