Editing Jumping spider (section)

== Behavior ==

===Jumping===
[[File:Unidentified Salticid Jumping with Trailing Dragline.jpg|thumb|Unidentified salticid jumping with trailing dragline]]
Many other arthropods are known to jump, including [[grasshopper]]s, [[flea]]s, [[leafhopper]]s, and [[Talitridae|sand fleas]]. Jumping spiders are different from these animals because they are able to make accurate, targeted jumps. Jumps are used for navigation, to escape danger, and to catch prey. When jumping, they use mainly their third or fourth pair of legs, or both pairs, depending on species.<ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046696/ Role of legs and foot adhesion in salticid spiders jumping from smooth surfaces]</ref> Jumping spiders' well-developed internal [[hydraulics|hydraulic]] system extends their limbs by altering the pressure of their body fluid ([[hemolymph]]) within them.<ref name="ParBrow1959">{{cite journal|author1=Parry, D.A. |author2=Brown, R.H.J |title= The jumping mechanism of salticid spiders |journal= Journal of Experimental Biology |year=1959|volume= 36 |issue=4|pages= 654–664|doi=10.1242/jeb.36.4.654 |bibcode=1959JExpB..36..654P |url=https://journals.biologists.com/jeb/article/36/4/654/13286/The-Jumping-Mechanism-of-Salticid-Spiders|url-access=subscription }}</ref> This enables the spiders to jump without having large muscular legs like a [[grasshopper]]. The maximum horizontal jump distance varies greatly between species, with some capable of jumping two or three body lengths, while the jump of an individual ''[[Colonus puerperus]]'' was measured at 38 times the body length.<ref name="Hill2018">{{cite journal|author1=Hill, D.E. |title= The jumping behavior of jumping spiders: a review |journal= Peckhamia |year=2018|volume= 167 |issue=1|pages= 1–8|url=https://peckhamia.com/peckhamia/PECKHAMIA_167.1.pdf }}</ref> The accuracy of their jumps is mediated by their well-developed visual system and the ability to quickly process visual information to tailor each jump.<ref name="Hill2006">{{cite web |author1=Hill, D.E. |title=Targeted jumps by salticid spiders (Araneae, Salticidae, ''Phidippus'') |version=v. 9 |website=The Peckham Society |date=15 December 2006 | url=https://www.peckhamia.com/epublications/Hill%202006%20Targeted%20jumps%20by%20salticid%20spiders%20V9%20EB%20PDF.pdf}}</ref><ref name="HarLiJack2012">{{cite book |last1=Harland |first1=D.P. |last2=Li |first2=D. |last3=Jackson |first3=R.R.|year=2012 |editor-last1=Lazareva |editor-first1=O.F. |editor-last2=Shimizu |editor-first2=T |title=How Animals See the World: Comparative behavior, biology, and evolution of vision |publisher=Oxford University Press |orig-date=1st pub. 2012 |pages=133–163 |chapter=Chapter 9: How Jumping Spiders See the World |chapter-url= https://academic.oup.com/book/10753/chapter-abstract/158855659?redirectedFrom=fulltext&login=false |isbn= 978-0-19-993316-7}}</ref> When a jumping spider moves from place to place, and especially just before it jumps, it [[tether]]s a filament of [[Spider silk|silk]] (or 'dragline') to whatever it is standing on.<ref name=RichEdwaCutl05/><ref name=BBCLargest/> This dragline provides a mechanical aid to jumping, including braking and stabilization<ref name="Hill2006"/><ref name="CheLiaTsaChi2013">{{cite journal|author1=Chen, Y. |author2=Ciao, C. |author3=Tsai, F. |author4=Chi, K.  |title= More than a safety line: jump-stabilizing silk of salticids |journal= Journal of the Royal Society Interface |year=2013|volume= 10:20130572 |issue=87 |doi=10.1098/rsif.2013.0572 |pmid=23925983 |pmc=3758018 }}</ref> and if the jump should fail, the spider climbs back up the dragline.<ref name="Rainer F. Foelix p. 11"/>

===Hunting===
[[File:JumpingSpider hunt macrogiants A.jpg|thumb|342x342px|[[Hyllus semicupreus|Heavy-bodied jumper]] eating a [[Plexippus paykulli|Pantropical jumper]], another jumping spider]]
The hunting behaviour of the Salticidae is confusingly varied compared to that of most spiders in other families.<ref name="RDBJRR1">{{cite journal|author1=Richman, David B. |author2=Jackson, Robert R. |title= A review of the ethology of jumping spiders (Araneae, Salticidae)|journal= Bull. Br. Arachnol. Soc. |year=1992|volume= 9 |issue=2|pages= 33–37|url=http://www.peckhamia.com/hosted/Richman%20Jackson%201992%20A%20review%20of%20the%20ethology%20of%20jumping%20spiders.pdf}}</ref> Salticids hunt diurnally as a rule, which is consistent with their highly developed visual system. When it detects potential prey, a jumping spider typically begins orienting itself by swiveling its [[cephalothorax]] to bring the anterior median eyes to bear. It then moves its [[abdomen]] into line with its cephalothorax. After that, it might spend some time inspecting the object of its attention and determining whether a camouflaged or doubtful item of prey is promising, before it starts to stalk slowly forward. When close enough, the spider pauses to attach a dragline, then springs onto the prey.

Many variations on the theme and many surprising aspects exist. For one, salticids do not necessarily follow a straight path in approaching prey. They may follow a circuitous course, sometimes even a course that takes the hunter through regions from which the prey is not visible. Such complex adaptive behaviour is hard to reconcile with an organism that has such a tiny brain, but some jumping spiders, in particular some species of [[Portia (spider)|''Portia'']], can negotiate long detours from one bush down to the ground, then up the stem of another bush to capture a prey item on a particular leaf.<ref>{{Cite journal|last1=TARSITANO|first1=MICHAEL S.|last2=JACKSON|first2=ROBERT R.|date=February 1997|title=Araneophagic jumping spiders discriminate between detour routes that do and do not lead to prey|journal=Animal Behaviour|volume=53|issue=2|pages=257–266|doi=10.1006/anbe.1996.0372|s2cid=53180070|issn=0003-3472}}</ref> Such behaviour still is the subject of research.<ref name="RDBJRR1"/>

Some salticid species are continually on the move, stopping periodically to look around for prey, which they then stalk immediately. Others spend more time scanning their surroundings from one position, actively stalking any prey they detect. Members of the genus ''Phaeacius'' take that strategy to extremes; they sit on a tree trunk, facing downwards and rarely do any stalking, but simply lunge down on any prey items that pass close before them.<ref name="RDBJRR1"/>

Some Salticidae specialise in particular classes of prey, such as [[ant]]s. Most spiders, including most salticids, avoid worker ants, but several species not only eat them as a primary item in their diets, but also employ specialised attack techniques; ''[[Anasaitis canosa]]'', for example, circles around to the front of the ant and grabs it over the back of its head. Such [[Myrmecophagy|myrmecophagous]] species, however, do not necessarily refuse other prey items, and routinely catch flies and similar prey in the usual salticid fashion, without the special precautions they apply in hunting dangerous prey such as ants. Ants offer the advantages of being plentiful prey items for which little competition from other predators occurs, but catching less hazardous prey when it presents itself remains profitable.<ref name="RDBJRR1"/>

Some of the most surprising hunting behaviours occur among the [[List of feeding behaviours|araneophagous]] Salticidae, and vary greatly in method. Many of the spider-hunting species quite commonly attack other spiders, whether fellow salticids or not, in the same way as any other prey, but some kinds resort to web invasion; nonspecialists such as ''[[Phidippus audax]]'' sometimes attack prey ensnared in webs, basically in acts of [[kleptoparasitism]]; sometimes they leap onto and eat the web occupant itself, or simply walk over the web for that purpose.

Salticidae in the genera ''[[Brettus]]'', ''[[Cyrba]]'', ''[[Gelotia]]'', and ''[[Portia (spider)|Portia]]'' display more advanced web-invasion behavior. They slowly advance onto the web and vibrate the silk with their pedipalps and legs. In this respect, their behaviour resembles that of the [[Mimetidae]], probably the most specialised of the araneophagous spider families. If the web occupant approaches in the manner appropriate to dealing with ensnared prey, the predator attacks.<ref name="RDBJRR1"/>

The foregoing examples present the Salticidae as textbook examples of active hunters; they would hardly seem likely to build webs other than those used in reproductive activities, and in fact, most species really do not build webs to catch prey. However, exceptions occur, though even those that do build capture webs generally also go hunting like other salticids. Some ''Portia'' species, for example, spin capture webs that are functional, though not as impressive as some orb webs of the [[Orb-weaver spider|Araneidae]]; ''Portia'' webs are of an unusual funnel shape and apparently adapted to the capture of other spiders. ''[[Spartaeus]]'' species, though, largely capture moths in their webs. In their review of the [[ethology]] of the Salticidae, Richman and Jackson speculate on whether such web building is a relic of the evolution of this family from web-building ancestors.<ref name="RDBJRR1"/>

In hunting, the Salticidae also use their silk as a tether to enable them to reach prey that otherwise would be inaccessible. For example, by advancing towards the prey to less than the jumping distance, then retreating and leaping in an arc at the end of the tether line, many species can leap onto prey on vertical or even on inverted surfaces, which of course would not be possible without such a tether.

Having made contact with the prey, hunting Salticidae administer a bite to inject rapid-acting venom that gives the victim little time to react.<ref>[https://www.youtube.com/watch?v=qxbuysNGLOM National Geographic video of capture of bee by jumping spider]. Youtube.com (27 February 2009). Retrieved on 4 May 2013.</ref> In this respect, they resemble the Mimetidae and Thomisidae, families that ambush prey that often are larger than the predator, and they do so without securing the victim with silk; they accordingly must immobilise it immediately and their venom is adapted accordingly.

{{multiple image
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 | footer = This small female jumping spider (''[[Hyllus semicupreus]]'') successfully captured a grasshopper that is much larger and stronger than she is. The grasshopper tried to escape, but the spider immobilized it using the venom she injected, and the "dragline" helped her hold her position with respect to the prey object.
 | image1 = Jumping spider hunting a grasshopper at Kadavoor.jpg
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 | image2 = Jumping spider hunting a grasshopper in Kadavoor.jpg
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 | image3 = Jumping spider hunting a grasshopper by Kadavoor.jpg
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=== Sleeping ===
Among several organisms, scientists have discovered that octopuses and cuttlefish experience REM sleep. Although REM sleep has been proved to be a phase of sleep in various organisms, there was a lack of evidence that supported the presence of REM sleep in insects and arachnids.(Mason, 2022){{citation needed|date=November 2024}}