Hamster wheel

{{Short description|Exercise toy for hamsters and other rodents}} {{About|the exercise device for rodents|the Australian television satirical comedy series|The Hamster Wheel}} thumb|Wooden hamster wheel, size 21cm [[File:Phodopus sungorus - Hamsterkraftwerk.jpg|thumb|Like other rodents, hamsters are highly motivated to run in wheels.]]

A '''hamster wheel''' or '''running wheel''' is an exercise device used primarily by hamsters and other rodents, but also by other cursorial animals when given the opportunity. Most of these devices consist of a runged or ridged wheel held on a stand by a single or pair of stub axles. Hamster wheels allow rodents to run even when their space is confined. The earliest dated use of the term "hamster wheel", located by the Oxford English Dictionary, is in a 1949 newspaper advertisement.<ref>''Los Angeles Times'', 9 Oct. 1949, p. B20/4 (advt.), referenced in ''Oxford English Dictionary'', Draft Additions, Sep. 2007, under entry "Hamster."</ref> Squirrel cages featured in an 1876 and 1885 catalog by Osborn Manufacturing Co''.'' came with running wheels for the squirrels, similar to hamster wheels.<ref>{{Cite web |title=A Squirrel's Life – Smithsonian Libraries and Archives / Unbound |url=https://blog.library.si.edu/blog/2014/05/12/a-squirrels-life/ |url-status=live |archive-url=https://web.archive.org/web/20200328023345/https://blog.library.si.edu/blog/2014/05/12/a-squirrels-life/ |archive-date=2020-03-28 |access-date=2024-08-17 |website=Smithsonian Libraries and Archives |language=en-US}}</ref><ref>{{Cite book |last=Osborn Manufacturing Co. (New York |first=N. Y. ) |url=https://archive.org/details/catalogueofsolem00osbo/page/18/mode/2up |title=Catalogue of sole manufacturers of the Osborn patent metallic finish bird and animal cages: also directions for the care of birds. |date=1976 |publisher=The Company |others=Winterthur Museum Library}}</ref>

==Preferences== Choice tests with Syrian hamsters (''Mesocricetus auratus'') have shown that they prefer larger wheels; the animals chose a wheel diameter of {{convert|35|cm|in|abbr=on}} over {{convert|23|cm|in|abbr=on}},<ref name=reebs>{{cite journal|last1=Reebs|first1=S. G.|year= 2005|title= Running wheel choice by Syrian hamsters|journal= Laboratory Animals|volume= 39|pages=442–451|doi=10.1258/002367705774286493|pmid=16197712|last2=St-Onge|first2=P|issue=4|s2cid=21311908}}</ref> which itself was preferred over {{convert|17.5|cm|in|abbr=on}}.<ref name=mrosovsky>{{cite journal|last1=Mrosovsky|first1=N.|year= 1998|title= Revolutionary science: an improved running wheel for hamsters|journal= Chronobiology International|volume= 15|pages=147–158|last2=Salmon|first2=P.A.|last3=Vrang|first3=N.|issue=2|pmid=9562919|doi=10.3109/07420529808998679}}</ref>

Hamsters showed no preference between a relatively uniform running surface made of plastic mesh and a surface made of rungs spaced 9&nbsp;mm apart, although they did prefer the mesh compared to rungs spaced 12&nbsp;mm apart, most likely because of the wider space between the rungs allowed their legs to slip through.<ref name=reebs/> The hamsters neither preferred nor avoided wheels that had small "speed bumps" installed along the running surface to provide environmental enrichment.<ref name=reebs/>

Choice tests with mice have also shown a preference for larger wheels (17.5&nbsp;cm over 13&nbsp;cm in diameter) and a preference for plastic mesh over rungs and over solid plastic as a running surface.<ref>Banjanin, S., and Mrosovsky, N., 2000, Preferences of mice, ''Mus musculus'', for different types of running wheel, Laboratory Animals, 34: 313–318.</ref> More acrobatic species, such as the canyon mouse (''Peromyscus crinitus'') and the deer mouse (''Peromyscus maniculatus'') can develop preferences for wheels that force the animals to jump, such as square wheels or wheels with hurdles along the running surface.<ref>Kavanau, J.L., and Brant, D.H., 1965, Wheel-running preferences of ''Peromyscus'', Nature, 208: 597–98</ref><ref>Kavanau, J.L., 1966, Wheel-running preferences of mice, Zeitschrift für Tierpsychologie 23: 858–66</ref><ref>Kavanau, J.L., 1967, Behavior of captive white-footed mice, Science, 155: 1623–39.</ref>

==Use by animals== [[File:Ocicat on Cat Wheel.webm|thumb|An ocicat on a running wheel]] Like other rodents, hamsters are highly motivated to run on wheels; it is not uncommon to record distances of {{convert|9|km|mi|abbr=on}} being run in one night. Other 24-h records include {{convert|43|km|mi|abbr=on}} for rats, {{convert|31|km|mi|abbr=on}} for wild mice, {{convert|19|km|mi|abbr=on}} for lemmings, {{convert|16|km|mi|abbr=on}} for laboratory mice, and {{convert|8|km|mi|abbr=on}} for gerbils.<ref name=sherwin>Sherwin, C.M., 1998, Voluntary wheel running: A review and novel interpretation, Animal Behaviour, 56: 11–27</ref> Hypotheses to explain such high levels of running in wheels include a need for activity, substitute for exploration, and stereotypic behaviour. However, free wild mice will run on wheels installed in the field, which speaks against the notion of stereotypic behavior induced by captivity conditions.<ref>{{citation |title=Wheel running in the wild |last1=Meijer |first1=Johanna H. |last2=Robbers |first2=Yuri |journal=Proceedings of the Royal Society B |volume=281 |issue=1786 |article-number=20140210 |doi=10.1098/rspb.2014.0210|pmid=24850923 |pmc=4046404 |year=2014 }}</ref> Alternatively, various experimental results strongly indicate that wheel running, like play or the endorphin or endocannabinoid<ref>Raichlen, D. A., A. D. Foster, G. L. Gerdeman, A. Sellier, and A. Giuffrida. 2012. Wired to run: exercise-induced endocannabinoid signaling in humans and cursorial mammals with implications for the 'runner's high'. Journal of Experimental Biology 215:1331-1336.</ref> release associated with the 'runner's high', is self-rewarding.<ref name=sherwin/><ref name="Novak et al., (2012)">Novak, C.M., Burghardt, P.R. and Levine, J.A., 2012, The use of a running wheel to measure activity in rodents: Relationship to energy balance, general activity, and reward, Neuroscience and Biobehavioral Reviews, 36: 1001–1014</ref><ref>Belke, T.W., and Wagner, J.P. 2005. The reinforcing property and the rewarding aftereffect of wheel running in rats: a combination of two paradigms. Behavioral Processes 68: 165-172.</ref> Wheel use is highly valued by several species as shown in consumer demand studies which require an animal to work for a resource, i.e. bar-press or lift weighted doors.<ref name=sherwin/><ref>Belke, T.W. and Garland, T., Jr., 2007, A brief opportunity to run does not function as a reinforcer for mice selected for high daily wheel-running rates, Journal of the Experimental Analysis of Behavior, 88: 199-213</ref> This makes running wheels a popular type of enrichment to the captivity conditions of rodents.

Captive animals continue to use wheels even when provided with other types of enrichment. In one experiment, Syrian hamsters that could use tunnels to access five different cages each containing a toy showed no more than a 25% reduction in running-wheel use compared to hamsters housed in a single cage without toys (except for the running wheel).<ref>{{cite journal|last1=Reebs|first1=S.G.|last2=Maillet|first2=D.|date=2003|title=Effect of cage enrichment on the daily use of running wheels by Syrian hamsters|journal=Chronobiology International|volume=20|issue=1|pages=9–20|doi=10.1081/CBI-120018329|pmid=12638687|s2cid=21925891}}</ref> In another study, female Syrian hamsters housed with a nestbox, bedding, hay, paper towels, cardboard tubes, and branches used a wheel regularly and benefitted from it as indicated by showing less stereotypic bar-gnawing and producing larger litters of young compared to females kept under the same conditions but without a wheel.<ref>Gebhardt-Henrich, S.G., Vonlanthen, E.M., and Steiger, A., 2005, How does the running wheel affect the behavior and reproduction of golden hamsters kept as pets, Applied Animal Behaviour Science, 95: 199-203.</ref> Laboratory mice were prepared to perform more switch presses to enter a cage containing a running wheel compared to several meters of Habitrail tubing or a torus of Habitrail tubing.<ref name="Sherwin, (1998)">Sherwin, C.M., 1998, The use and perceived importance of three resources which provide caged laboratory mice the opportunity of extended locomotion, Applied Animal Behaviour Science, 55: 353-367.</ref> Canyon mice provided with wheels stopped exploring new areas of a complex burrow-simulating maze and spent less time revisiting already-explored areas.<ref>Brant, D.H. and Kavanau, J.L. 1965. Exploration and movement patterns of the canyon mouse Peromyscus crinitus in an extensive laboratory enclosure. Ecology 46: 452-461.</ref>

Running in wheels can be so intense in hamsters that it may result in foot lesions, which appear as small cuts on the paw pads or toes.<ref>{{cite journal|last1=Beaulieu|first1=A.|last2=Reebs|first2=S.G.|date=2009|title=Effects of bedding material and running wheel surface on paw wounds in male and female Syrian hamsters|journal=Laboratory Animals|volume=43|issue=1|pages=85–90|doi=10.1258/la.2008.007088|pmid=19001065|s2cid=22308514}}</ref><ref>{{cite journal|last1=Veillette|first1=M.|last2=Guitard|first2=J.|last3=Reebs|first3=S.G.|date=2010|title=Cause and possible treatments of foot lesions in captive Syrian hamsters (''Mesocricetus auratus'')|journal=Veterinary Medicine International|volume=2010|article-number=951708|doi=10.4061/2010/951708|pmid=20613965|pmc=2896862 |doi-access=free }}</ref> Such paw wounds rapidly scab over and do not prevent hamsters from continuing to run in their wheel.

A hamster in a running wheel equipped with a generator can generate up to 0.5&nbsp;mW electric power on average, enough for illuminating small LED lamps.<ref>{{Cite web|title=A Hamster-Powered World|url=https://theechohsmse.com/963/humor/a-hamster-powered-world/|website=The Echo|access-date=2025-11-27|first=Ronald|last=Szeto}}</ref>

==Use in science== Voluntary wheel running is one of the most widely used indicators of activity and wake-time in research on circadian rhythms and other aspects of chronobiology.<ref>Dunlap, J.C., Loros, J.J., and DeCoursey, P.J. 2004. Chronobiology: Biological Timekeeping. Sinauer Associates, Sunderland MA.</ref> Miniature running wheels have even been used to measure the circadian locomotor activity of cockroaches<ref>Binkley, S. 1990. The clockwork sparrow: time, clocks, and calendars in biological organisms. Prentice-Hall, Englewood Cliffs NJ.</ref><ref>Roberts. S. 1965. Photoreception and entrainment of cockroach activity rhythms. Science 148: 958-959.</ref> and the cricket Teleogryllus commodus.<ref>Loher, W. 1979. The effect of male calling on female locomotor activity of Teleogryllus commodus. Behavioral Ecology and Sociobiology 5: 383-390.</ref><ref>Yagi, K.J. and Loher, W. 1986. Circadian locomotory rhythm and the influence of moulting in Australian field cricket nymphs. Physiological Entomology 11: 97-105.</ref> For rodents, running wheels are easier to set up and automate than other techniques of activity recording such as bar-gnawing<ref>Morin, L. 1978. Rhythmicity of hamster gnawing: Ease of measurement and similarity to running activity. Physiology and Behavior 21: 317-320</ref> and spring-suspended or knife-edge balanced cages.<ref>Aschoff, J., Figala, J., and Poppel, E. 1973. Circadian rhythms of locomotor activity in the golden hamster (Mesocricetus auratus) measured with two different techniques. Journal of Comparative and Physiological Psychology 85: 20-28.</ref>

In rodents, voluntary exercise is almost always measured by the use of wheels. This makes running wheels the tool of choice in research on the effects of exercise and voluntary activity on metabolism, obesity, and pain.<ref>Garland, T., Jr., H. Schutz, M. A. Chappell, B. K. Keeney, T. H. Meek, L. E. Copes, W. Acosta, C. Drenowatz, R. C. Maciel, G. van Dijk, C. M. Kotz, and J. C. Eisenmann. 2011. The biological control of voluntary exercise, spontaneous physical activity and daily energy expenditure in relation to obesity: human and rodent perspectives. Journal of Experimental Biology 214:206-229.</ref><ref>Coutinho A.E., Fediuc S., Campbell J.E., and Riddell, M.C. 2006. Metabolic effects of voluntary wheel running in young and old Syrian golden hamsters. Physiology and Behavior 87: 360-367.</ref><ref>Gattermann R., Weinandy R., and Fritzsche P. 2004. Running-wheel activity and body composition in golden hamsters (''Mesocricetus auratus''). Physiology and Behavior 82: 541-544.</ref><ref>Kandasamy, R., Calsbeek, J. J., & Morgan, M. M. (2016). Home cage wheel running is an objective and clinically relevant method to assess inflammatory pain in male and female rats. Journal of Neuroscience Methods, 263, 115-122.</ref><ref>Cobos, E. J., Ghasemlou, N., Araldi, D., Segal, D., Duong, K., & Woolf, C. J. (2012). Inflammation-induced decrease in voluntary wheel running in mice: a nonreflexive test for evaluating inflammatory pain and analgesia. PAIN®, 153(4), 876-884.</ref>

The neurotransmitter systems involved in wheel-running behavior have received considerable study.<ref>Rhodes, J.S., Gammie, S.C. and Garland, T., Jr., 2005, Neurobiology of mice selected for high voluntary wheel-running activity, Integrative and Comparative Biology, 45: 438-455.</ref> Recent evidence suggests that changes in both dopaminergic and serotonergic tone alter running-wheel activity. For example, one study in mice has shown that several antidepressant medications (all of which directly or indirectly enhance serotonergic tone) suppress running-wheel activity without suppressing general locomotion.<ref>{{cite journal|last=Weber|first=M|author2=Talmon S |author3=Schulze I |author4=Boeddinghaus C |author5=Gross G |author6=Schoemaker H |author7=Wicke KM |title=Running wheel activity is sensitive to acute treatment with selective inhibitors for either serotonin or norepinephrine reuptake|journal=Psychopharmacology|date=May 2009|volume=203|issue=4|pages=753–762|doi=10.1007/s00213-008-1420-4|pmid=19104776|s2cid=25424870}}</ref> The endocannabinoid system also contributes to wheel running in a sex-specific manner in rodents.<ref>Keeney, B.K., Meek, T.H., Middleton, K.M., Holness, L. F. and Garland, T., Jr., 2012, Sex differences in cannabinoid receptor-1 (CB1) pharmacology in mice selectively bred for high voluntary wheel-running behavior, Pharmacology Biochemistry and Behavior, 101: 528-537.</ref> Mice from lines that have been selectively bred for high levels of voluntary wheel running have altered responsiveness to drugs that alter dopamine and endocannabinoid signalling, and enlarged midbrains.<ref>Kolb, E. M., E. L. Rezende, L. Holness, A. Radtke, S. K. Lee, A. Obenaus, and T. Garland, Jr. 2013. Mice selectively bred for high voluntary wheel running have larger midbrains: support for the mosaic model of brain evolution. Journal of Experimental Biology 216:515-523.</ref>

==Animal welfare considerations== Tierärztliche Vereinigung für Tierschutz (TVT) recommends wheels should be at least 20&nbsp;cm (8") for dwarf hamsters and at least 30&nbsp;cm (12") for Syrian hamsters, since smaller diameters lead to permanent spinal curvatures, especially in young animals. They also recommend a solid running surface because rungs or mesh can cause injury.<ref name="Leaflet No. 62">{{cite web |title=Leaflet No. 62 - Pets, accessories contrary to animal welfare |url=https://www.tierschutz-tvt.de/alle-merkblaetter-und-stellungnahmen/#c270 |website=TVT |access-date=21 June 2020 |location=Germany |language=de |format=PDF}}</ref> It has been published in several books about small pet care as far back as 2000 that rungs and mesh wheels can cause injuries.<ref name="Hamsters">{{cite book |last1=Meredith |first1=Susan |title=Hamsters |date=2000 |publisher=Tulsa, Okla. : EDC Pub. |page=30 |isbn=978-0-7945-0796-1 |url=https://archive.org/details/hamsters0000mere |access-date=21 June 2020}}</ref><ref name="Caring for your hamster">{{cite book |last1=Hill |first1=Lorraine |title=Caring for your hamster |date=2004 |publisher=Franklin, TN : Dalmatian Press |page=64 |isbn=978-1-4037-0885-4 |url=https://archive.org/details/caringforyourham0000hill |access-date=21 June 2020}}</ref><ref name="Hamster">{{cite book |last1=Rayner |first1=Matthew |title=Hamster |date=2004 |publisher=Milwaukee, Wis. : Gareth Stevens |isbn=978-0-8368-4617-1 |url=https://archive.org/details/hamster00rayn/ |access-date=21 June 2020}}</ref><ref name="Hamster: a practical guide">{{cite book |last1=Alderton |first1=David |title=Hamster: a practical guide to caring for your hamster |date=2002 |publisher=Collins |location=London |page=128 |isbn=978-0-00-712282-0 |url=https://archive.org/details/hamster0000alde/ |access-date=21 June 2020}}</ref><ref name="Looking after your pet Hamster">{{cite book |last1=Hibbert |first1=Clare |title=Looking after your pet Hamster |date=2004 |publisher=Smart Apple Media |page=32 |isbn=978-1-58340-433-1 |url=https://archive.org/details/hamster0000hibb/ |access-date=21 June 2020}}</ref>

Most wheels are constructed of steel, wood or plastic, each having advantages and disadvantages. Solid wheels are safer for all animals because the animal's feet or legs cannot get trapped and injured between rungs. There are wheels in all these materials that are solid. Plastic wheels are fine for some animals. However, some rodents (e.g. gerbils or degus) will quickly chew and destroy plastic wheels but not steel versions.

Guinea pigs cannot use exercise wheels, and attempting to use one may cause injury to a guinea pig.<ref>{{cite web |title=Guinea Pig Care Guide |url=https://www.guinealynx.info/healthycavy_orig.html#exercise |website=Guinea Lynx |access-date=7 September 2023}}</ref>

==Hamster ball== thumb|right|A mouse in a green hamster ball{{see also|Hamster ball}} A related exercise device, the hamster ball, is a hollow plastic ball into which a pet can be temporarily placed. The ball allows the pet to freely roll around on the floor to explore and exercise while preventing escape.

Recent theory suggests that hamster balls are not ideal for exercise outside of the cage. The balls prevent the rodent from using touch (whiskers) and smell to navigate the area.{{Citation needed|reason=Website does not exist and appears to have been an opinion, not a primary source.|date=April 2026}} It also restricts airflow and can catch toes or tails in the slits meant for airflow.{{Citation needed|reason=This is improperly cited and links to an article with no obvious connection to the topic.|date=April 2026}}

==Running disc== thumb|right|Dwarf hamsters using a running disc A related exercise device is a running disc. This is a rotatable shallow bowl, or slightly concave disc, which is set at an angle to the horizontal.<ref>De Bono, J. P., D. Adlam, D. J. Paterson, and K. M. Channon. 2005. Novel quantitative phenotypes of exercise training in mouse models. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 290:R926–R934.</ref> Some commercial refuges for caged rodents have a disc mounted on the roof at a slight angle. The rodents run on the rim of the disc in a similar way to running in hamster wheels.

==See also== * Hamster care * Hamster cage * Behavioral enrichment * Treadmill * Treadwheel * Treadwheel crane {{clear}}

==References== {{reflist|30em}}

==External links== {{Commons category|Hamster wheels}}

Category:Ethology Category:Animal welfare Category:Articles containing video clips Category:Hamster equipment Category:Wheels