Meet the Texas indigo. The species range of the big, nonvenomous snake stretches from south Texas to the northern parts of Mexico. These snakes eat anything they can catch: mice, birds, lizards, frogs, and other snakes—even rattlesnakes.

Unlike some species of snake, indigos do not depend on the darkness to hunt their prey. They are diurnal and search for food during the day. Despite this, Texas indigo snakes are not always out in the open and often find shelter in shade or the abandoned burrows of other animals.

Texas indigo snakes are among the largest snakes native to the United States. The record length of an indigo snake is 2.6 meters (8.5 feet)! Both the eastern indigo snake (indigenous to Florida) and the Texas indigo are classified as threatened species by the U.S. Fish & Wildlife Service. Texas indigo snakes are protected in the state of Texas and cannot be hunted or killed. 

  1. The scientific name of the Texas indigo snake is Drymarchon melanurus erebennus. Drymarchon is the genus, melanurus is the species, and erebennus is the subspecies. What is the difference between genus, species, and subspecies?

    • Answer

      Genus, species, and subspecies are all taxonomic rankings of organisms.

      • Genus and species are the most specific taxonomic rankings of all organisms. Genus is the larger unit. Species that have many common physical or behavioral characteristics share a genus. An organism’s genus and species make up its binomial name, sometimes called its scientific name. Every living thing on Earth, from indigo snakes to human beings, has a binomial name. (We’re Homo sapiens.)
      • Some (not all) organisms have an even smaller taxonomic unit of classification, called a subspecies. All subspecies share common characteristics. Middle American indigo snakes (Drymarchon melanurus) have five subspecies, while human beings have one—we’re Homo sapiens sapiens.

  2. Drymarchon, the indigo snake genus, is made up of several species. How do scientists differentiate between genus and species? In other words, what makes a species a species?

    • Answer

      Two individuals belong to the same species if they can breed and create fertile offspring. Texas indigo snakes cannot reproduce with eastern indigo snakes, for instance. They share a genus, but they’re different species.

  3. What adaptations do indigo snakes need to live in hot environments like southern Texas and northern Mexico?

    • Answer

      Answers will vary!

      One common adaptation is the ability to find microclimates, such as caves or burrows, that are cooler than out in the open. The Texas indigo is a large snake and not very proficient at digging its own shelter. Instead, it often slides into pre-made, abandoned burrows left by other desert animals. 




small hole or tunnel used for shelter.


active during the day.


animal that is hunted and eaten by other animals.


native, geographic area in which an organism can be found. Range also refers to the geographic distribution of a particular species.

threatened species

organism that may soon become endangered.


having to do with venom or organisms that secrete venom.