Editing Snake (section)

== Behavior and life history ==
[[File:Snake found in wood chips.jpg|thumb|Snake coiled on a stick in [[Oklahoma]]. It was [[brumation|brumating]] in a large pile of wood chips, found by this [[landscaper]] after he bulldozed the pile in late autumn 2018.|197x197px]]
=== Winter dormancy ===
[[File:A snake coiled in the cavity of a tree.jpg|thumb|235x235px|A snaked coiled in the cavity of a tree]]
In regions where winters are too cold for snakes to tolerate while remaining active, local species will enter a period of [[Dormancy#Brumation|brumation]]. Unlike [[Dormancy#Hibernation|hibernation]], in which the dormant mammals are actually asleep, brumating reptiles are awake but inactive. Individual snakes may brumate in burrows, under rock piles, or inside fallen trees, or large numbers of snakes may clump together in [[Hibernaculum (zoology)|hibernacula]].<ref>{{Cite web |last=Gabriel |first=Angeli |date=2022-11-30 |title=Where do snakes go in the winter? |url=https://www.foxweather.com/earth-space/snakes-winter |access-date=2025-04-30 |website=FOX Weather |language=en-US}}</ref>

=== Feeding and diet ===
[[File:Eierschlange frisst Zwergwachtelei.jpg|thumb|upright|[[Dasypeltis|African egg-eating snake]] eating an egg]][[File:PikiWiki Israel 37648 Nature and Colors.jpg|thumb|upright|''[[Dolichophis jugularis]]'' preying on a [[sheltopusik]] ]]
[[File:Eastern Hognose Defense.jpg|thumb|[[Eastern hognose snake|Eastern hognose]] hooding.]]
All snakes are [[hypercarnivore|strictly carnivorous]], [[Predation|preying]] on small animals including lizards, frogs, other snakes, small mammals, birds, eggs, fish, snails, worms, and insects.<ref name="Meh87" />{{Rp|81}}<ref name="Sanchez" />{{sfn|Behler|King|1979|p=581}} Snakes cannot bite or tear their food to pieces so must swallow their prey whole. The eating habits of a snake are largely influenced by body size; smaller snakes eat smaller prey. Juvenile pythons might start out feeding on lizards or mice and graduate to small deer or antelope as an adult, for example.{{Citation needed|date=November 2024}}

The snake's [[jaw]] is a complex structure. Contrary to the popular belief that snakes can dislocate their jaws, they have an extremely flexible [[mandible|lower jaw]], the two halves of which are not rigidly attached, and numerous other joints in the skull, which allow the snake to open its mouth wide enough to swallow prey whole, even if it is larger in diameter than the snake itself.{{sfn|Behler|King|1979|p=581}} For example, the [[Dasypeltis|African egg-eating snake]] has flexible jaws adapted for eating eggs much larger than the diameter of its head.<ref name="Meh87" />{{Rp|81}} This snake has no teeth, but does have bony protrusions on the inside edge of its [[Vertebral column|spine]], which it uses to break the shell when eating eggs.<ref name="Meh87" />{{Rp|81}}

The majority of snakes eat a variety of prey animals, but there is some specialization in certain species. [[King cobra]]s and the Australian [[Vermicella annulata|bandy-bandy]] consume other snakes. Species of the family [[Pareidae]] have more teeth on the right side of their mouths than on the left, as they mostly prey on snails and the shells usually spiral clockwise.<ref name="Meh87" />{{Rp|184}}<ref>{{cite journal |vauthors=Hoso M, Asami T, Hori M |title=Right-handed snakes: convergent evolution of asymmetry for functional specialization |journal=[[Biology Letters]] |volume=3 |issue=2 |pages=169–72 |date=April 2007 |pmid=17307721 |pmc=2375934 |doi=10.1098/rsbl.2006.0600}}</ref><ref>{{cite journal |vauthors=Pyron RA, Burbrink FT, Wiens JJ |title=A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes |journal=[[BMC Evolutionary Biology]] |volume=13 |pages=93 |date=April 2013 |issue=1 |pmid=23627680 |pmc=3682911 |doi=10.1186/1471-2148-13-93 |bibcode=2013BMCEE..13...93P |doi-access=free }}</ref>

Some snakes have a venomous bite, which they use to kill their prey before eating it.{{sfn|Behler|King|1979|p=581}}{{sfn|Freiberg|Walls|1984|pp=125–127}} Other snakes kill their prey by [[constriction]],{{sfn|Behler|King|1979|p=581}} while some swallow their prey when it is still alive.<ref name="Meh87" />{{Rp|81}}{{sfn|Behler|King|1979|p=581}}

After eating, snakes become dormant to allow the process of [[digestion]] to take place;<ref name="Rosenfeld_11"/> this is an intense activity, especially after consumption of large prey. In species that feed only sporadically, the entire [[intestine]] enters a reduced state between meals to conserve energy. The digestive system is then 'up-regulated' to full capacity within 48&nbsp;hours of prey consumption. Being [[ectothermic]] ("cold-blooded"), the surrounding temperature plays an important role in the digestion process. The ideal temperature for snakes to digest food is {{convert|30|°C|°F}}. There is a huge amount of [[metabolism|metabolic]] energy involved in a snake's digestion, for example the surface body temperature of the South American rattlesnake (''[[Crotalus durissus]]'') increases by as much as {{convert|1.2|C-change|sigfig=2}} during the digestive process.<ref>{{cite journal |vauthors=Tattersall GJ, Milsom WK, Abe AS, Brito SP, Andrade DV |title=The thermogenesis of digestion in rattlesnakes |journal=The Journal of Experimental Biology |volume=207 |issue=Pt 4 |pages=579–85 |date=February 2004 |pmid=14718501 |doi=10.1242/jeb.00790 |doi-access=free|bibcode=2004JExpB.207..579T }}</ref> If a snake is disturbed after having eaten recently, it will often [[vomiting|regurgitate]] its prey to be able to escape the perceived threat. When undisturbed, the digestive process is highly efficient; the snake's digestive [[enzymes]] dissolve and absorb everything but the prey's hair (or feathers) and claws, which are excreted along with [[uric acid|waste]].{{Citation needed|date=November 2024}}

=== Hooding and spitting ===
Hooding (expansion of the neck area) is a visual deterrent, mostly seen in cobras (elapids), and is primarily controlled by rib muscles.<ref>{{cite journal |last1=Young |first1=Bruce A. |last2=Kardong |first2=Kenneth V. |title=The functional morphology of hooding in cobras |journal=Journal of Experimental Biology |date=May 2010 |volume=213 |issue=9 |pages=1521–1528 |doi=10.1242/jeb.034447 |pmid=20400637 |bibcode=2010JExpB.213.1521Y }}</ref> Hooding can be accompanied by spitting venom towards the threatening object,<ref>{{cite journal |last1=Young |first1=Bruce A. |last2=Dunlap |first2=Karen |last3=Koenig |first3=Kristen |last4=Singer |first4=Meredith |title=The buccal buckle: the functional morphology of venom spitting in cobras |journal=Journal of Experimental Biology |date=15 September 2004 |volume=207 |issue=20 |pages=3483–3494 |doi=10.1242/jeb.01170 |pmid=15339944 |bibcode=2004JExpB.207.3483Y }}</ref> and producing a specialized sound; hissing. Studies on captive cobras showed that 13–22% of the body length is raised during hooding.<ref>{{Cite journal |first1=Alireza |last1=Nasoori |first2=Delavar |last2=Shahbazzadeh |first3=Toshio |last3=Tsubota |first4=Bruce A. |last4=Young |date=Winter 2016 |title=The defensive behaviour of ''Naja oxiana'', with comments on the visual displays of cobras |number=138 |url=https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-138-winter-2016/960-04-the-defensive-behaviour-of-i-naja-oxiana-i-with-comments-on-the-visual-displays-of-cobras |journal=The Herpetological Bulletin |access-date=3 May 2021 |archive-date=3 May 2021 |archive-url=https://web.archive.org/web/20210503094608/https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-138-winter-2016/960-04-the-defensive-behaviour-of-i-naja-oxiana-i-with-comments-on-the-visual-displays-of-cobras |url-status=live }}</ref>

=== Locomotion ===
The lack of limbs does not impede the movement of snakes. They have developed several different modes of locomotion to deal with particular environments. Unlike the gaits of limbed animals, which form a continuum, each mode of snake locomotion is discrete and distinct from the others; transitions between modes are abrupt.{{sfn|Cogger|Zweifel|1992|p=175}}<ref name = "Gray">{{cite journal |vauthors=Gray J |title=The mechanism of locomotion in snakes |journal=The Journal of Experimental Biology |volume=23 |issue=2 |pages=101–20 |date=December 1946 |doi=10.1242/jeb.23.2.101 |pmid=20281580|bibcode=1946JExpB..23..101G }}</ref>

==== Lateral undulation ====
{{Main|Undulatory locomotion}}
[[File:Foot prints of Snake.jpg|thumb|Crawling prints of a snake]]
Lateral undulation is the sole mode of aquatic locomotion, and the most common mode of terrestrial locomotion.<ref name = "Gray"/> In this mode, the body of the snake alternately flexes to the left and right, resulting in a series of rearward-moving "waves".{{sfn|Cogger|Zweifel|1992|p=175}} While this movement appears rapid, snakes have rarely been documented moving faster than two body-lengths per second, often much less.<ref name = "Hekrotte">{{Cite journal |last=Hekrotte |first=Carlton |name-list-style=vanc |title = Relations of Body Temperature, Size, and Crawling Speed of the Common Garter Snake, Thamnophis s. sirtalis |journal=[[Copeia]] |year=1967 |volume=23 |issue=4 |pages=759–763 |doi=10.2307/1441886 |jstor=1441886}}</ref> This mode of movement has the same net cost of transport (calories burned per meter moved) as running in lizards of the same mass.<ref name = "Walton">{{cite journal |vauthors=Walton M, Jayne BC, Bennet AF |title=The energetic cost of limbless locomotion |journal=[[Science (journal)|Science]] |volume=249 |issue=4968 |pages=524–7 |date=August 1990 |pmid=17735283 |doi=10.1126/science.249.4968.524 |bibcode=1990Sci...249..524W |s2cid=17065200}}</ref>

Terrestrial lateral undulation is the most common mode of terrestrial locomotion for most snake species.{{sfn|Cogger|Zweifel|1992|p=175}} In this mode, the posteriorly moving waves push against contact points in the environment, such as rocks, twigs, irregularities in the soil, etc.{{sfn|Cogger|Zweifel|1992|p=175}} Each of these environmental objects, in turn, generates a reaction force directed forward and towards the midline of the snake, resulting in forward thrust while the lateral components cancel out.<ref name = "Gray_lissman"/> The speed of this movement depends upon the density of push-points in the environment, with a medium density of about 8{{clarify|What does this refer to? What scale?|date=June 2016}} along the snake's length being ideal.<ref name = "Hekrotte"/> The wave speed is precisely the same as the snake speed, and as a result, every point on the snake's body follows the path of the point ahead of it, allowing snakes to move through very dense vegetation and small openings.<ref name="Gray_lissman">{{cite journal |last1=Gray |first1=J. |last2=Lissmann |first2=H. W. |title=The Kinetics of Locomotion of the Grass-Snake |journal=Journal of Experimental Biology |date=February 1950 |volume=26 |issue=4 |pages=354–367 |doi=10.1242/jeb.26.4.354 |bibcode=1950JExpB..26..354G }}</ref>

When swimming, the waves become larger as they move down the snake's body, and the wave travels backwards faster than the snake moves forwards.<ref name = "Gray2">{{Cite journal |vauthors=Gray J |title=Undulatory propulsion |journal=[[Quarterly Journal of Microscopical Science]] |year=1953 |volume=94 |pages=551–578}}</ref> Thrust is generated by pushing their body against the water, resulting in the observed slip. In spite of overall similarities, studies show that the pattern of muscle activation is different in aquatic versus terrestrial lateral undulation, which justifies calling them separate modes.<ref name = "Jayne1">{{cite journal |vauthors=Jayne BC |title=Muscular mechanisms of snake locomotion: an electromyographic study of lateral undulation of the Florida banded water snake (Nerodia fasciata) and the yellow rat snake (Elaphe obsoleta) |journal=[[Journal of Morphology]] |volume=197 |issue=2 |pages=159–81 |date=August 1988 |pmid=3184194 |doi=10.1002/jmor.1051970204 |s2cid=25729192}}</ref> All snakes can laterally undulate forward (with backward-moving waves), but only sea snakes have been observed reversing the motion (moving backwards with forward-moving waves).{{sfn|Cogger|Zweifel|1992|p=175}}

==== Sidewinding ====
{{Main|Sidewinding}}
[[File:Neonate sidewinder sidewinding with tracks unlabeled.jpg|thumb|right|A neonate sidewinder rattlesnake (''[[Crotalus cerastes]]'') sidewinding]]
Most often employed by colubroid snakes ([[colubrids]], [[elapids]], and [[Viperidae|vipers]]) when the snake must move in an environment that lacks irregularities to push against (rendering lateral undulation impossible), such as a slick mud flat, or a sand dune, sidewinding is a modified form of lateral undulation in which all of the body segments oriented in one direction remain in contact with the ground, while the other segments are lifted up, resulting in a peculiar "rolling" motion.{{sfn|Cogger|Zweifel|1992|p=177}}<ref name = "Jayne2">{{Cite journal |vauthors=Jayne BC |title=Kinematics of terrestrial snake locomotion |journal=[[Copeia]] |year=1986 |pages=915–927 |doi=10.2307/1445288 |volume=1986 |issue=4 |jstor=1445288}}</ref> The sidewinder moves forward by throwing a loop of itself and then pulling itself up by it. By lowering its head the snake gets leverage, straightening itself out and pressing itself against the ground, it brings itself forward and at an angle that leaves it ready for the next jump. The head and the loop are in effect the two feet upon which the snake walks. The snake's body, appearing roughly perpendicular to its direction, may bewilder the observer, since preconception may lead one to associate snake movement with a head that leads and a body that follows. It appears the sidewinder is going sideways - but precisely where the snake is going, where it wants to go, the head gives clear indication. The snake leaves behind a trail that looks like a series of hooks one after the next. Snakes can move backwards to retreat from an enemy, though they normally do not.{{sfn|Campbell|Shaw|1974}}{{page needed|date=April 2024}} This mode of locomotion overcomes the slippery nature of sand or mud by pushing off with only static portions on the body, thereby minimizing slipping.{{sfn|Cogger|Zweifel|1992|p=177}} The static nature of the contact points can be shown from the tracks of a sidewinding snake, which show each belly scale imprint, without any smearing. This mode of locomotion has very low caloric cost, less than {{frac|1|3}} of the cost for a lizard to move the same distance.<ref name="Walton"/> Contrary to popular belief, there is no evidence that sidewinding is associated with the sand being hot.{{sfn|Cogger|Zweifel|1992|p=177}}

==== Concertina ====
{{Main|Concertina movement}}
When push-points are absent, but there is not enough space to use sidewinding because of lateral constraints, such as in tunnels, snakes rely on concertina locomotion.{{sfn|Cogger|Zweifel|1992|p=175}}<ref name = "Jayne2"/> In this mode, the snake braces the posterior portion of its body against the tunnel wall while the front of the snake extends and straightens.{{sfn|Cogger|Zweifel|1992|p=177}} The front portion then flexes and forms an anchor point, and the posterior is straightened and pulled forwards. This mode of locomotion is slow and very demanding, up to seven times the cost of laterally undulating over the same distance.<ref name="Walton"/> This high cost is due to the repeated stops and starts of portions of the body as well as the necessity of using active muscular effort to brace against the tunnel walls.{{Citation needed|date=November 2024}}

==== Arboreal ====
[[File:Golden tree snake.jpg|thumb|left|[[Golden tree snake]] climbing a flower]]
The movement of snakes in arboreal habitats has only recently been studied.<ref name = "Astley">{{cite journal |vauthors = Astley HC, Jayne BC |title=Effects of perch diameter and incline on the kinematics, performance and modes of arboreal locomotion of corn snakes (Elaphe guttata) |journal=The Journal of Experimental Biology |volume=210 |issue=Pt 21 |pages=3862–72 |date=November 2007 |pmid=17951427 |doi=10.1242/jeb.009050 |s2cid=18129284 |doi-access=|bibcode=2007JExpB.210.3862A }}</ref> While on tree branches, snakes use several modes of locomotion depending on species and bark texture.<ref name="Astley"/> In general, snakes will use a modified form of concertina locomotion on smooth branches, but will laterally undulate if contact points are available.<ref name="Astley"/> Snakes move faster on small branches and when contact points are present, in contrast to limbed animals, which do better on large branches with little 'clutter'.<ref name="Astley"/>

Gliding snakes (''[[Chrysopelea]]'') of Southeast Asia launch themselves from branch tips, spreading their ribs and laterally undulating as they glide between trees.{{sfn|Cogger|Zweifel|1992|p=177}}{{sfn|Freiberg|Walls|1984|p=135}}<ref>{{cite journal |vauthors=Socha JJ |title=Gliding flight in the paradise tree snake |journal=[[Nature (journal)|Nature]] |volume=418 |issue=6898 |pages=603–4 |date=August 2002 |pmid=12167849 |doi=10.1038/418603a |bibcode=2002Natur.418..603S |s2cid=4424131}}</ref> These snakes can perform a controlled glide for hundreds of feet depending upon launch altitude and can even turn in midair.{{sfn|Cogger|Zweifel|1992|p=177}}{{sfn|Freiberg|Walls|1984|p=135}}

==== Rectilinear ====
{{Main|Rectilinear locomotion}}
The slowest mode of snake locomotion is rectilinear locomotion, which is also the only one where the snake does not need to bend its body laterally, though it may do so when turning.{{sfn|Cogger|Zweifel|1992|p=176}} In this mode, the belly scales are lifted and pulled forward before being placed down and the body pulled over them. Waves of movement and stasis pass posteriorly, resulting in a series of ripples in the skin.{{sfn|Cogger|Zweifel|1992|p=176}} The ribs of the snake do not move in this mode of locomotion and this method is most often used by large [[Pythonidae|python]]s, [[Boidae|boa]]s, and [[Viperidae|viper]]s when stalking prey across open ground as the snake's movements are subtle and harder to detect by their prey in this manner.{{sfn|Cogger|Zweifel|1992|p=177}}