You don’t want to use one too small. The probe should just fit inside the opening when you perform the procedure. [3] X Research source However, don’t ever use one over 4 millimeters on a corn snake. [4] X Research source
Make sure the person is supporting most of the snake’s body with her hands, especially the middle part of the body. [6] X Research source You can also have her control the head by placing gentle pressure on either side of the head at the base. The reason you don’t grasp the snake underneath the head is that it can cut off breathing. [7] X Research source
The reason you probe a snake is to see how far the probe goes. If it goes a longer way in, you have a male snake. If it goes a short way in, you have a female snake. Essentially, when you are inserting it along one of his hemipenes, one of two of his inverted genitalia. A female doesn’t have these parts, so you won’t be able to go as far. [12] X Research source
Remember to only perform this technique on hatchlings.
Applying excessive force could cause tissue damage to the snake. Make sure you don’t press too hard. Before you try this procedure for yourself it is best to be shown what to do by an expert, such as a specialist reptile vet or a trained herpetologist.
Males will also be longer from the cloaca to the tip, but that is difficult to distinguish if you don’t have another snake for a comparison. [21] X Research source
If you can’t see it very well, try taking a picture and zooming in.
