The main difference I am aware of is the mature size. A Mexican milk will be between 2-3 feet long as an adult and Nelson's can regularly get over that and are more likely to be in the 4 foot range. I believe Nelson's are more likely to have white on the nose rather than the pure black head that the Mexican's have and that their white bands tend to be narrower than those on Mexican's, especially the first one on the neck. The normal colored Nelson's I have seen have white narrow bands and Mexican's have narrow bands that range between white and dark orange. My impression is also that the red on Nelson's is a purer red, less orange tinged than on Mexican's - and the red segments are proportionally longer - but that is just a personal impression. Seems albino Nelson's are more common than the normal variety - at least around here.
Pic of our Mexican milksnake - they are a great little milksnake,
mary v.
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