heterozygous means that the snake will look normal but will carry the trait to look like a pied. Basically it has only half of the genes to make the snake look like a pied.

the percentages are a representation of the chances the snake will be carrying the trait. So if you breed a snake that is a pied to a normal you know that the resulting snakes will get the pied trait. So they are 100% het pied. You know for sure they are carrying the trait. But if you breed one of these het pieds to a normal you are not guaranteed that the resulting snakes will get the trait. So thats when you start getting the 66% and 50% labels. Do a google search on punnet squares for more information.

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