The Western hooknose snake (Gyalopion canum) is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of small colubrid

Colubrid

A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...

 snake

Snake

Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

 native to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, from western Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 to southeastern Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, and into northern and central Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. It was once classified in the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Ficimia

Ficimia

Ficimia is a genus of colubrid snakes commonly known as hooknose snakes or hook-nosed snakes. There are seven species within the genus.-Geographic range:...

, but was reclassified due to distinct morphological

Comparative anatomy

Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...

 characteristics. It is sometimes referred to as the Chihuahuan hook-nosed snake because it is commonly found in the Chihuahuan Desert

Chihuahuan Desert

The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...

.

Description

The Western hooknose snake is a small species, growing to 18-28 cm (7-11 inches) long. They are gray or gray brown in color, with 25-48 dark brown or black blotches down their back, and a cream colored underside. They have a slightly upturned snout, which gives them their common name.

Behavior

Hooknose snakes are nocturnal

Nocturnal animal

Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is "nocturnal"....

 burrowers, most often found under rocks. They prefer slightly sandy habitats, near a permanent water source. Their diet

Diet (nutrition)

In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...

 consists primarily of spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s and centipede

Centipede

Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. Centipedes have an odd number of pairs of...

s. They are oviparous.

One of its primary defensive behaviors is to make a popping noise with its cloaca

Cloaca

In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...

, i.e., farting. According to an article in the August, 2000 issue of Discover magazine, during a laboratory experiment carried out by Bruce Young, a morphologist at Lafayette College

Lafayette College

Lafayette College is a private coeducational liberal arts and engineering college located in Easton, Pennsylvania, USA. The school, founded in 1826 by James Madison Porter,son of General Andrew Porter of Norristown and citizens of Easton, first began holding classes in 1832...

, the snakes only farted when they felt threatened, and some farted so energetically that they lifted themselves off the ground. http://discovermagazine.com/2000/aug/breakpop