Snake — Description, Habitat, Image, Diet, and Interesting Facts
- 1 Snake
- 2 Description of the Snake
- 3 Interesting Facts About the Snake
- 4 Habitat of the Snake
- 5 Distribution of the Snake
- 6 Brumination
- 7 Snake and Human Interaction
- 8 Snake Care
- 9 Behavior of the Snake
- 10 Reproduction of the Snake
- 11 A large-scale screening for the taiga tick, Ixodes persulcatus, and the meadow tick, Dermacentor reticulatus, in southern Scandinavia, 2016
- 12 Abstract
- 13 Availability of data and materials
- 14 References
- 15 Acknowledgements
- 16 Funding
Just about everyone knows what a Snake is. These creatures have long bodies, no legs, and their skin has a covering of scales. Most species also have extremely flexible jaws, or even possess extra joints, so that they can swallow prey larger than themselves!
Researchers recognize about 3,600 different species of Snakes. They categorize these reptiles into the suborder Serpentes, and separate them further into 20 different families. Read on to learn about the Snake.
Description of the Snake
These creatures have long bodies, tapered tails, and no legs. Though some species do have rough scales, in the vast majority the scales carefully overlap one another. This means their skin in smooth when you rub in the direction of the scales.
With such an incredible range of species, it is no surprise that these reptiles come in a variety of sizes. The smallest species grow just 4 in. long as adults, while the largest species exceed 22 ft. long or more!
Interesting Facts About the Snake
This creature has an incredible variety of traits and adaptations that make it unique. Learn what makes the Snake so interesting below.
- Venom vs. Poison – Some species have hollow fangs that they use to inject venom, which helps incapacitate their prey. This is quite different from poison, which certain animals have in or on their skin, which causes harm when another animal bites or eats it.
- Poisonous Snakes – In most cases, if you call a Snake “poisonous” you would be incorrect. However, there are some that actually secrete poison! The Rhabdophis genus of keelback Snakes is both venomous and poisonous. Some species of garter Snakes also retain the poison of the prey that they eat.
- Titanoboa – One extinct species actually reached terrifying lengths. Archeologists have found fossils of the titanoboa at lengths up to 42 ft. long!
- Venomous Volume – Of the thousands of different species, researchers estimate that just 15% produce venom. Even if a species has venom, that doesn’t mean that they can actually pose a danger to humans. Scientists believe that just a small percentage of the world’s population is dangerous to man.
Habitat of the Snake
Different species live in a wide variety of habitats. You can find some species in the driest desert, and some in the wettest tropical rainforest. They also live in woodlands, grasslands, meadows, forests, taiga, and virtually any habitat that isn’t arctic or sub-arctic.
Many also live in close proximity to humans, in areas like farms, parks, gardens, and even suburbs. They utilize the rats and mice that thrive in areas with high human populations.
Distribution of the Snake
You can find Snakes on almost every single landmass, and even in some oceans! The only areas without these reptiles are the Arctic and Antarctic.
They live in North, Central, and South America, as well as Eurasia, Africa, and Australasia. Sea Snakes, also known as Kraits, live in the seas of Australasia, and coastal regions of the Indian Ocean.
Different species feed on different types of prey. Generally, these creatures are carnivores, which means that they eat meat. As discussed earlier, their hinged or double-jointed jaws allow them to feed on prey much larger than their heads. Their hunting method varies, many species lie still and ambush prey as it passes by. Other species actively search for and pursue prey.
Some species specialize in certain types of prey, like fish, insects, rodents, and more. Conversely, some species eat just about anything they can catch and fit in their mouths. Depending on the species, they eat rats, mice, rabbits, birds, eggs, other reptiles, frogs, and much more.
You’ve probably heard of hibernation, but have you heard of brumation? Animals that brumate are quite similar to those that hibernate. Species that live in cold regions usually brumate during the coldest months of winter. During brumation, these reptiles remain awake, but they are inactive. Mammals that hibernate are asleep during their period of inactivity.
Some species congregate in large numbers during their brumation period. A region where many individuals group together to brumate is known as a hibernaculum. Garter Snakes famously brumate in massive hibernacula. This video shows one example of a likely hibernaculum of rattlesnakes, do make sure you ignore the comment of “slimy reptiles” at the end – Snakes are never slimy!
Snake and Human Interaction
These reptiles get a really bad rep’ from humans. In many places, people even kill harmless species, just because they fear Snakes. Sadly, the vast majority of species pose no threat to humans, children, or pets. In fact, many even helpfully remove pesky rats and mice.
Humans killing them, hunting them for their meat or skin, and destroying their habitat, impacts different species in different ways. Some species have strong populations and human activity doesn’t cause as much damage. For other species, people drive them towards the brink of extinction.
Humans have not domesticated any species of Snake.
Does the Snake Make a Good Pet
Yes! Some species make wonderful pets. It is important to understand that different types of care go into housing reptiles, and they are not like owning a dog or cat. When purchasing any type of pet, you must make sure that the breeder is reputable and ethical. You should also ensure the animal was captive-bred and not captured from the wild.
Each species has different needs. Different sizes need different enclosures, and different species need different temperatures, humidity, substrates, and basking areas. Please do your research for that specific species of Snake to ensure that you keep them in the best conditions for them.
Most reptiles need a heat source, a basking location, and some way to regulate humidity. Tropical species need high humidity, while those living in arid regions need low humidity. Many species thrive on a diet of insects, mice, rats, and similar food sources.
Behavior of the Snake
Typically, these creatures live solitary lives. As discussed previously, some do congregate in large numbers to brumate. While most species spend their days basking and foraging for food, some species prefer nocturnal behavior.
Individual behavior varies drastically based on the species. Some spend all their lives high in the trees, foraging for food in the branches and hiding in cavities from predators. Others live on the ground, or even burrow underground.
Reproduction of the Snake
It is virtually impossible to categorize all of these reptiles into a single reproductive category. In many species, after mating the females lay their eggs underground, in rotting tree stumps, or similar situations. A few species even wrap their bodies around the eggs to aid incubation.
Many species give “live birth.” Known as ovoviviparous breeders, they develop the eggs within their bodies, and the young hatch while inside the mothers. A few species are viviparous, and their embryos develop internally via placenta.
A select few species can actually reproduce without the presence of a male, known as parthenogenesis. Females which have never had access to a male partner can develop fertile eggs and give birth to young asexually.
The taiga tick, Ixodes persulcatus, has previously been limited to eastern Europe and northern Asia, but recently its range has expanded to Finland and northern Sweden. The species is of medical importance, as it, along with a string of other pathogens, may carry the Siberian and Far Eastern subtypes of tick-borne encephalitis virus. These subtypes appear to cause more severe disease, with higher fatality rates than the central European subtype. Until recently, the meadow tick, Dermacentor reticulatus, has been absent from Scandinavia, but has now been detected in Denmark, Norway and Sweden. Dermacentor reticulatus carries, along with other pathogens, Babesia canis and Rickettsia raoultii. Babesia canis causes severe and often fatal canine babesiosis, and R. raoultii may cause disease in humans. We collected 600 tick nymphs from each of 50 randomly selected sites in Denmark, southern Norway and south-eastern Sweden in August–September 2016. We tested pools of 10 nymphs in a Fluidigm real time PCR chip to screen for I. persulcatus and D. reticulatus, as well as tick-borne pathogens. Of all the 30,000 nymphs tested, none were I. persulcatus or D. reticulatus. Our results suggest that I. persulcatus is still limited to the northern parts of Sweden, and have not expanded into southern parts of Scandinavia. According to literature reports and supported by our screening results, D. reticulatus may yet only be an occasional guest in Scandinavia without established populations.
Letter to the Editor
Tick-borne diseases pose a risk to both humans and animals [1,2,3], and there is a concern that the increase in incidence and geographical range reported over the last decades [4,5,6,7,8] may be an effect of climate change impacting vectors and their associated pathogens [9, 10]. In Europe, and especially Scandinavia, the main vector of disease-causing pathogens in humans, pets and other large mammals is the castor bean tick Ixodes ricinus [6, 7]. The closely related taiga tick, Ixodes persulcatus, has previously been limited to eastern Europe and northern Asia , but within the last 15 years, the species has expanded its range, both in eastern Europe [12, 13] but also towards western Europe [11, 12, 14]. Ixodes persulcatus was recorded in the western parts of Finland in 2004  and 2008 , and in northern Sweden in 2015 . Ixodes persulcatus may carry the Siberian and Far Eastern subtypes of the tick-borne encephalitis virus (TBEV) along with a range of other pathogens [11, 16, 17]. The Siberian and Far Eastern subtypes of TBEV have been reported to cause more severe symptoms than the European sub-type [17,18,19], although there is speculation that this may be due to other factors such as clinical alert and reporting [17, 19].
The meadow tick, Dermacentor reticulatus, is endemic to Europe , and is currently spreading to new geographical areas [20,21,22]. Dermacentor reticulatus was previously absent from Scandinavia , but has been found on migrating birds in Norway as early as 2003–2005 , and potentially in 2009, as Babesia canis was detected in a dog from the Oslo area that had not travelled abroad, indicating that D. reticulatus was present in the area . In Sweden, single D. reticulatus has been identified in 2010 in the region of Skåne, in 2012 on a dog that had been abroad and then again two more times in the region of Skåne in 2017 . In Denmark, D. reticulatus was found on a migrating golden jackal (Canis aureus) in 2017 , and again in 2018 on a dog that was returning from a trip to Slovakia with its owner . Dermacentor reticulatus carries several pathogens presently absent in Scandinavia, but the most concerning involve B. canis and Rickettsia raoultii. Babesia canis causes canine babesiosis in dogs with a high risk of death . Rickettsia raoultii poses a zoonotic health concern as it may cause disease in humans .
As a part of a large Scandinavian project, we randomly selected 30 sites in each of Denmark, southern Norway and south-eastern Sweden for tick collection in August and September 2016. Selection of the 90 sites was based on a stratification scheme with random sampling described in Kjær et al. . Ticks were only analysed from sites where ≥ 600 nymphs could be collected, resulting in a total of 50 sites (Fig. 1).
Map of southern Scandinavia with the 50 sample sites from 2016 depicted (blue dots). At each site, a minimum of 600 tick nymphs were collected. The red ellipse marks the area where I. persulcatus was recorded in 2015 by Jaenson et al. . The blue ellipses are where D. reticulatus/B. canis was found associated with dogs [24, 25], the magenta ellipse is where D. reticulatus was found on birds  and the green ellipses is where D. reticulatus has been found in nature 
We morphologically examined the 30,000 ticks to ensure that they were all nymphs. We aggregated 30,000 collected nymphs into 60 pools of 10 for each site and used the BioMark real-time PCR system (Fluidigm, San Francisco, California, USA) for high-throughput microfluidic RT-PCR. The method is thoroughly described in Klitgaard et al.  and Michelet et al. . Along with 18 different pathogens, we simultaneously screened each pool for presence of D. reticulatus, I. persulcatus and I. ricinus, as described and validated by Michelet et al. . The Fluidigm chip has been used for surveillance of tick-borne pathogens and exotic tick species on both flagged ticks and on ticks removed from imported animals in Denmark since 2014. The chip has previously detected D. reticulatus on a migrating golden jackal .
We found that of the 30,000 nymphs tested, all pools tested positive for I. ricinus, and none for I. persulcatus or D. reticulatus. Using simple probability theory, we calculated a measure of “freedom from I. persulcatus/D. reticulatus”, using the binomial theorem:
where DC is the degree of certainty (here 95%), prev is the proportion of I. persulcatus/D. reticulatus, and N is the sample size, here either 600 per site or 30,000 in total.
With this equation, we assume that if I. persulcatus/D. reticulatus constitute a proportion higher or equal to prev in all nymphs collected and the PCR is 100% sensitive in pool sizes of 10, we can then be 95% certain that we would detect at least one positive pool. With 600 ticks per site and all pools negative, we are therefore 95% certain that the proportion of I. persulcatus/D. reticulatus at each given site was lower than 0.5%, given the reasonable assumption that the 600 nymphs represent a random sample drawn from a much larger population at the site. Likewise, if the 30.000 nymphs collected in total were a random sample from the entire area, we would be 95% certain that the proportion of I. persulcatus/D. reticulatus would be lower than 0.01%. Therefore, if the two species are individually introduced by e.g. migrating birds to the region, they constitute less than one out of 10,000 flagged nymphs. However, if the two species are not just randomly introduced individuals but instead have become established breeding populations then they are likely to have a spatially clustered distribution in the area. With small clusters the probability of detecting a cluster by screening 50 sites is just 5.8% at a 95% certainty level, assuming the proportion of the species in a cluster is high enough to be detected with a sensitivity of 100% when 600 nymphs are tested per site. Thus, the existence of spatially limited clusters of locally breeding I. persulcatus or D. reticulatus in the area cannot be excluded with reasonable certainty, despite the large number of nymphs analysed.
Although there is no evidence for an increased northward distribution of permanent viable populations of I. ricinus in Norway , studies from Sweden have found I. ricinus to have expanded northwards compared to historical data , possibly due to climate change [9, 10]. Thus, a potential spread of I. persulcatus further south in Scandinavia and establishment of D. reticulatus within the Scandinavian region could also be expected. Further tick surveillance studies in Scandinavia should acknowledge the possibility of I. persulcatus/D. reticulatus becoming established further in this region, and thus the possibility of infections with the Siberian and Far Eastern subtypes of TBEV, B. canis, R. raoultii and other pathogens related to these two tick species. It may be advisable to carry out targeted surveillance by flagging at sites with reported cases of B. canis in dogs and Siberian and Far Eastern subtypes of TBE in humans without recent travel histories. Alternatively, it may be recommendable to initiate citizen science projects  as local breeding populations of I. persulcatus and D. reticulatus will be difficult to detect by random surveillance. Our results suggest that I. persulcatus and D. reticulatus may not be established in southern Scandinavia.
Availability of data and materials
The datasets analysed during the current study are available from the corresponding author on reasonable request.
Pfäffle M, Littwin N, Muders SV, Petney TN. The ecology of tick-borne diseases. Int J Parasitol. 2013;43:1059–77.
Han BA, Yang L. Predicting novel tick vectors of zoonotic disease. In: ICML workshop on #Data4Good: machine learning in social good applications, New York, NY; 2016. arXiv:1606.06323.
de la Fuente J, Estrada-Pena A, Venzal JM, Kocan KM, Sonenshine DE. Overview: ticks as vectors of pathogens that cause disease in humans and animals. Front Biosci. 2008;13:6938–46.
Estrada-Peña A, De J, de la Fuente J. The ecology of ticks and epidemiology of tick-borne viral diseases. Antivir Res. 2014;108:104–28.
Vu Hai V, Almeras L, Socolovschi C, Raoult D, Parola P, Pagès F, et al. Monitoring human tick-borne disease risk and tick bite exposure in Europe: available tools and promising future methods. Ticks Tick Borne Dis. 2014;5:607–19.
Jaenson TGT, Jaenson DGE, Eisen L, Petersson E, Lindgren E. Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden. Parasit Vectors. 2012;5:8.
Jensen PM, Skarphédinsson S, Jensen PM, Kristiansen K. Survey of tickborne infections in Denmark. Emerg Infect Dis. 2005;11:1055–61.
Michelet L, Delannoy S, Devillers E, Umhang G, Aspan A, Juremalm M, et al. High-throughput screening of tick-borne pathogens in Europe. Front Cell Infect Microbiol. 2014;4:103.
Gage KL, Burkot TR, Eisen RJ, Hayes EB. Climate and vectorborne diseases. Am J Prev Med. 2008;35:436–50.
Martens W, Jetten T, Rotmans J, Niessen L. Climate change and vector-borne diseases: a global modelling perspective. Glob Environ Change. 1995;5:195–209.
Jaenson TGT, Värv K, Fröjdman I, Jääskeläinen A, Rundgren K, Versteirt V, et al. First evidence of established populations of the taiga tick Ixodes persulcatus (Acari: Ixodidae) in Sweden. Parasit Vectors. 2016;9:377.
Bugmyrin SV, Bespyatova LA, Korotkov YS, Burenkova LA, Belova OA, Romanova LI, et al. Distribution of Ixodes ricinus and I. persulcatus ticks in southern Karelia (Russia). Ticks Tick Borne Dis. 2013;4:57–62.
Tokarevich NK, Tronin AA, Blinova OV, Buzinov RV, Boltenkov VP, Yurasova ED, et al. The impact of climate change on the expansion of Ixodes persulcatus habitat and the incidence of tick-borne encephalitis in the north of European Russia. Glob Health Action. 2011;4:8448.
Jaaskelainen A, Tikkakoski T, Uzcategui N, Alekseev A, Vaheri A, Vapalahti O. Siberian subtype tickborne encephalitis virus, Finland. Emerg Infect Dis. 2006;12:1568–71.
Jaaskelainen AE, Sironen T, Murueva GB, Subbotina N, Alekseev AN, Castren J, et al. Tick-borne encephalitis virus in ticks in Finland, Russian Karelia and Buryatia. J Gen Virol. 2010;91:2706–12.
Süss J. Tick-borne encephalitis 2010: epidemiology, risk areas, and virus strains in Europe and Asia. An overview. Ticks Tick Borne Dis. 2011;2:2–15.
Jääskeläinen A, Tonteri E, Pieninkeroinen I, Sironen T, Voutilainen L, Kuusi M, et al. Siberian subtype tick-borne encephalitis virus in Ixodes ricinus in a newly emerged focus, Finland. Ticks Tick Borne Dis. 2016;7:216–23.
Heyman P, Cochez C, Hofhuis A, van der Giessen J, Sprong H, Porter SR, et al. A clear and present danger: tick-borne diseases in Europe. Expert Rev Anti Infect Ther. 2010;8:33–50.
Lindquist L, Vapalahti O. Tick-borne encephalitis. Lancet. 2008;371:1861–71.
Földvári G, Široký P, Szekeres S, Majoros G, Sprong H. Dermacentor reticulatus: a vector on the rise. Parasit Vectors. 2016;9:314.
Klitgaard K, Chriél M, Isbrand A, Jensen TK, Bødker R. Identification of Dermacentor reticulatus ticks carrying Rickettsia raoultii on migrating jackal, Denmark. Emerg Infect Dis. 2017;23:2072–4.
Jongejan F, Ringenier M, Putting M, Berger L, Burgers S, Kortekaas R, et al. Novel foci of Dermacentor reticulatus ticks infected with Babesia canis and Babesia caballi in the Netherlands and in Belgium. Parasit Vectors. 2015;8:232.
Hasle G, Bjune G, Edvardsen E, Jakobsen C, Linnehol B, Røer JE, et al. Transport of ticks by migratory passerine birds to Norway. J Parasitol. 2009;95:1342–51.
Øines Ø, Storli K, Brun-Hansen H. First case of babesiosis caused by Babesia canis canis in a dog from Norway. Vet Parasitol. 2010;171:350–3.
Rudander SH. The risk of Dermacentor reticulatus establishing in Sweden (In Swedish, MSc Thesis). Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden; 2018.
Bødker R, Petersen RE, Kjær LJ, Isbrand A, Klitgaard K. Do not bring home the meadow tick from your vacation! Dansk Veterinær Tidsskr. 2018;8:42 (In Danish).
Solano-Gallego L, Sainz Á, Roura X, Estrada-Peña A, Miró G. A review of canine babesiosis: the European perspective. Parasit Vectors. 2016;9:336.
Kjær LJ, Soleng A, Edgar KS, Lindstedt HEH, Paulsen KM, Andreassen ÅK, et al. Predicting and mapping human risk of exposure to Ixodes ricinus nymphs using climatic and environmental data, Denmark, Norway and Sweden, 2016. Eurosurveillance. 2019;24:1800101.
Klitgaard K, Højgaard J, Isbrand A, Madsen JJ, Thorup K, Bødker R. Screening for multiple tick-borne pathogens in Ixodes ricinus ticks from birds in Denmark during spring and autumn migration seasons. Ticks Tick Borne Dis. 2019;10:546–52.
Soleng A, Edgar KS, Paulsen KM, Pedersen BN, Okbaldet YB, Skjetne IEB, et al. Distribution of Ixodes ricinus ticks and prevalence of tick-borne encephalitis virus among questing ticks in the Arctic Circle region of northern Norway. Ticks Tick Borne Dis. 2018;9:97–103.
Laaksonen M, Klemola T, Feuth E, Sormunen JJ, Puisto A, Mäkelä S, et al. Tick-borne pathogens in Finland: comparison of Ixodes ricinus and I. persulcatus in sympatric and parapatric areas. Parasit Vectors. 2018;11:556.
We thank Simon Friis-Wandall, Mette Frimodt Hansen, Caroline Greisen, Ana Carolina Cuellar, Najmul Haider, Leif Kristian Sortedal, Philip Thomassen Neset, Preben Ottesen, Alaka Lamsal, Ruchika Shakya, Martin Strnad, Hanne Quarsten, Sølvi Noraas, Åslaug Rudjord Lorentzen, Chiara Bertacco, Kevin Hohwald, Catharina Schmidt, Coco de Koning, and Wenche Okstad for assistance in the field. We would also like to thank the Danish Ministry of the Environment, The Forest and Nature Agency as well as many private landowners for allowing us access to their properties to conduct our sampling.
This study was funded by the Interreg V Program (the ScandTick Innovation project, Grant number 20200422), and the Danish Veterinary and Food Administration.