Nuevo Leon/Variable kingsnake, Lampropeltis mexicana thayeri

Origin: Mexico, northern portions of the Sierra Madre Oriental, primarily in the states of Nuevo Leon and Tamaulipas.

Size: 2-3 feet

Lifespan: up to 20 years

Basking Temperature: 85 degrees

Cool End Temperature: 75-80 degrees

Humidity: Dry

Substrate: Aspen

Baby enclosure size: 20″ x 10″ x 10″ (15qt – 10 gallon or equivalent)

Adult enclosure size: 24” x 12” x 16” (28-32 qt or 20 gallon long or equivalent)

Difficulty: Novice

Nuevo Leon (or Variable) kingsnakes  are a desert dwelling kingsnake endemic to Mexico. They are fascinating in their high degree of variation, from milk snake-like, to buckskin, gray, orange, and melanistic. Even two similar adults can produce litters with widely varied offspring. They are a small snake, typically 2 to 3 feet. They are elusive by nature but tame readily with minimal handling, although hatchlings can be quite skittish. While easy enough for novice keepers, their small size especially as hatchlings requires delicate handling that may be difficult for children.

This guide is a brief overview of basic care and minimum husbandry requirements and is not intended as a comprehensive guide to care. Our best advice:

Read, read, read! Studying about your new pet is the key to a long and happy life for them, and years of enjoyment for you.


Enclosures must be long enough for the snake to stretch out fully and exercise. These kingsnakes prefer to burrow rather than climb. Provide multiple hiding places. Upgrade your snake’s enclosure any time they are no longer able to stretch out. As humidity is not a substantial requirement for these animals, glass aquariums with screen tops are acceptable, though they are not our recommendation, as these snakes are excellent escape artists.


Aspen is ideal for these kingsnakes, and should be provided thick enough to allow burrowing. Remove any wet or mildewed substrate regularly.


A basking spot can be provided at one end of the enclosure regulated to 85 degrees. Ceramic heat emitters may be used with a guard to avoid burns (a screen lid is in effect a guard, but make sure the emitter is not touching the screen directly). An undertank heater will also work well.  Use a thermostat to regulate the temperature with the probe secured directly in the basing spot. Do not guess! Do not use only a thermometer. Overheating can be quickly fatal for your new pet. Basking spot may be cycled for day-night, with a constant ambient temp in the mid-70’s. These kingsnakes do not require UV lights.


These kingsnakes prefer a dry climate and do not need supplemental humidity. A humid hide with damp sphagnum moss may be provided to assist with shedding, but this is not typically needed.


Provide your snake with a non-porous water bowl and change it frequently. We find that because they move their bedding around frequently, a bowl with higher sides is preferable. Snakes frequently defecate in their water bowl, so frequent disinfection is essential. We recommend F10 Veterinary Disinfectant or original (yellow) Listerine diluted to 10% with water.


These kingsnakes should be handled regularly from the time they are young to develop into docile, well-socialized adults. Because they have little natural defenses, they frequently thrash and musk when picked up. When handling hatchling kingsnakes, we find it best to gently scoop them up with two hands, keeping them in the enclosure rather than removing them. This helps avoid falls, which can injure a young kingsnake. With regular handling, your young kingsnake will become more comfortable with being picked up. Young snakes that are being socialized may bite, but this is uncommon. The best reaction is no reaction. If children are handling hatchling snakes, adult supervision should always be provided.


Allow your new snake at least a week to adjust to its new habitat before feeding. Mortal Coil Serpentry supports feeding frozen feeders. Your new pet is already feeding on frozen thawed. Live feeding is not recommended. Warm frozen prey to a natural body temperature (~90 degrees). Do not feed your snake from your fingers. Present prey with tongs, holding it by the base of the tail, and wiggle gently in front of the snake. Do not handle for at least 24 hours after feeding. Mexican black kingsnakes will not typically eat when in shed.

Hatchlings to 2 years:

1 rodent the approximate girth of the snake once per week. Mice and African Soft Furs are superior to rats of equivalent size for nutritional value.

2+ years:

1 rodent the approximate girth of the snake once every 1-2 weeks. If the snake is refusing meals ~50% of the time, adjust the feeding schedule accordingly.

The correct body shape for a Nuevo Leon/Variable kingsnake is essentially round, but not so thick as to make the tail overly distinguishable from the body.