What Do Jumping Spiders Do in the Winter?

Most jumping spiders survive winter by entering a dormant state in a sheltered hiding spot, slowing their metabolism dramatically until warmer weather returns. Unlike insects that might migrate or die off after laying eggs, many jumping spider species overwinter as juveniles or subadults tucked into crevices, leaf litter, or even empty snail shells. The specifics vary by species and geography, and the biology behind their cold survival is more nuanced than simply “sleeping through it.”

Where Jumping Spiders Go When It Gets Cold

If you stop seeing jumping spiders on your windowsill or garden fence by late autumn, it is because they have retreated to protected microsites. A broad study of spider winter ecology found that roughly 84% of spiders overwinter in leaf litter or in vegetation near the ground, with only about 7% remaining without shelter in higher vegetation layers.¹ For jumping spiders specifically, the options include curling up under loose bark, burrowing into soil crevices, squeezing beneath rocks, nestling inside rolled-up dead leaves, or spinning a small silk retreat in a crack. These silk sacs act as tiny sleeping bags, providing a thin insulating layer and a barrier against wind and moisture.

Some species get surprisingly creative. In the Czech Republic, researchers documented three jumping spider species that overwinter inside empty terrestrial snail shells lying on the ground. The spiders seal themselves inside these shells with silk and wait out the cold months in what amounts to a tiny, naturally insulated capsule.² The choice of snail shell is not random. The surrounding microhabitat matters too, and males and females of the same species sometimes prefer different conditions. For instance, female Pellenes tripunctatus favored spots with a higher proportion of surrounding herbs, while males preferred areas with exposed soil.² That sex-based difference likely reflects different thermal or moisture needs, or possibly predator-avoidance strategies that diverge between the sexes.

What Stage of Life They Overwinter In

Not every jumping spider enters winter as an adult. In fact, most overwinter as immatures. Across the broader spider world, researchers have identified several distinct life-cycle strategies for getting through winter. The largest group of species, about 45% of the 277 species examined in one classic survey, reproduce in spring and summer and then hibernate as immatures. Another 23% are flexible, hibernating in different life stages depending on conditions.¹

Some jumping spiders follow multi-year development cycles that involve hibernating more than once. The sand-dwelling jumping spider Yllenus arenarius provides a striking example. Juveniles of this species emerge in early June and do not mature until the following August, over a year later. They mate in autumn and then hibernate for a second time, meaning a single spider passes through two full winters before its life cycle is complete.³ This pattern means populations living in the same habitat can end up isolated simply by being on different year-of-maturation schedules, an unusual quirk for such small animals.

For the jumping spiders you are most likely to encounter in North America, such as the bold jumping spider (Phidippus audax), overwintering typically happens in the subadult stage. They will have hatched and grown through several molts during the warm months, then pause their development over winter before reaching sexual maturity the following spring or early summer.

How They Handle the Cold Physiologically

Jumping spiders are ectotherms, so their body temperature tracks their surroundings. When winter arrives, they cannot generate body heat the way mammals do. Instead, they rely on a strategy called freeze avoidance. Rather than tolerating ice formation in their tissues, they keep their body fluids in a liquid state even below the freezing point of water. The temperature at which an animal’s body fluids spontaneously freeze is called the supercooling point, and it represents a hard lower limit: if the environment drops below it, the spider dies.

A study of bold jumping spiders from three populations across the United States, in Michigan, Oklahoma, and Texas, showed that supercooling points varied by geography. Spiders from Michigan, the coldest climate, froze at around −7.7 °C on average, while those from Texas froze at about −5.5 °C, and Oklahoma spiders fell in between at roughly −6.2 °C.⁴ That difference of about two degrees between the northernmost and southernmost populations may sound small, but for a tiny animal clinging to survival in a bark crevice, it can mean the difference between living and dying during a cold snap.

Body size also plays a role. Across all three populations, larger spiders had higher supercooling points, meaning they froze at warmer temperatures than smaller ones.⁴ This is a well-known pattern in cold-tolerance biology. Larger bodies have more water and more potential nucleation sites where ice crystals can begin forming, so they tend to freeze at higher temperatures. For a jumping spider heading into winter, being slightly smaller may actually confer a survival advantage in extreme cold.

Cryoprotectants and Chemical Preparation

Many overwintering arthropods produce antifreeze-like compounds to help their body fluids remain liquid at subzero temperatures. These cryoprotectants, typically sugars and sugar alcohols, work by depressing the freezing point of body fluids and by stabilizing cell membranes against cold damage. While most direct research on spider cryoprotectants has focused on wolf spiders rather than jumping spiders, the findings are still informative because the underlying physiology is similar across spider families.

In one wolf spider species studied through winter, researchers found accumulation of glycerol, myo-inositol, and several other cryoprotectant compounds. However, the levels were lower than what is typically seen in insects and other arthropods that hunker down for winter.⁵ The researchers noted that this modest cryoprotectant accumulation could leave winter-active spiders vulnerable during extreme cold events. The implication for jumping spiders is that chemical antifreeze is likely part of their winter toolkit, but probably not the whole story. Choosing the right microsite, one buffered from the most extreme temperatures, may matter just as much as internal chemistry.

Interestingly, the wolf spider study also showed that winter-active spiders actually continued to grow during the cold months, suggesting they were still feeding opportunistically.⁵ Whether jumping spiders do the same is less clear. Most evidence points to jumping spiders entering a deeper dormancy than wolf spiders, largely because jumping spiders are visual hunters that rely on excellent eyesight to stalk prey, and short winter days with weak light give them very little hunting opportunity.

Why Microsite Choice Matters So Much

A jumping spider’s survival through winter depends heavily on where it decides to settle before temperatures drop. The gap between ambient air temperature and the temperature inside a sheltered crevice, under a layer of leaf litter, or inside a snail shell can be several degrees. That buffer often means the spider never actually experiences temperatures near its supercooling point, even during the coldest nights.

The detailed preferences documented in the Czech snail-shell study show that microsite selection is not haphazard. The spiders evaluated the surrounding substrate, moisture levels, and vegetation cover before committing to a hibernation spot.² One species, Pellenes nigrociliatus, preferred rocky or stony surfaces with less moss, while P. tripunctatus sought out bare soil with more herbal cover. These are not trivial preferences. The type of substrate affects drainage and thermal buffering, while vegetation cover influences snow accumulation, which itself is an insulator. A thick layer of snow above a spider’s hiding spot can paradoxically keep it warmer by insulating the ground from frigid air above.

This is also why jumping spiders sometimes show up inside homes in autumn. They are not breeding indoors or establishing permanent residence in most cases. They are searching for a microsite that stays above their lethal temperature threshold, and the cracks around your window frame or the gap behind a baseboard look like excellent real estate to a spider that is, from its perspective, house hunting for the winter.

Northern Populations vs. Southern Populations

The geographic variation in cold tolerance seen in Phidippus audax reflects a broader pattern. Populations that regularly face harsh winters tend to have lower supercooling points than their relatives in milder climates. The Michigan population in the study cited earlier froze at temperatures roughly two degrees lower than the Texas population, and collection location was a statistically meaningful predictor of cold tolerance.⁴

Research on Habronattus jumping spiders along a desert elevation gradient in the southwestern United States adds another dimension. The species living at the highest elevation, where winter cold is most intense, had a lower critical thermal minimum than any of the other species living further downhill.⁶ The ability to function at lower temperatures appears to be one of the traits that allows certain species to occupy colder habitats. Temperature tolerance may, in fact, help draw the map of which jumping spider species live where, with cold tolerance acting as a gatekeeper for higher-elevation or higher-latitude ranges.

It is worth noting that all the Habronattus species in that study had essentially the same upper heat tolerance, regardless of elevation. Cold tolerance varied, but heat tolerance did not. This suggests that winter survival, not summer heat, is the selective pressure that differs most among populations and shapes species distributions.

What Kills Them Over Winter

Even with silk retreats, cryoprotectants, and carefully chosen microsites, plenty of jumping spiders do not make it through winter. The obvious threat is a sustained cold snap that drives temperatures below their supercooling point, especially when snow cover is thin or absent, removing the insulating blanket that normally protects ground-level hideouts.

But cold is not the only killer. Fungal pathogens represent an underappreciated threat. A global review of spider-pathogenic fungi found that jumping spiders (family Salticidae) are the spider family most frequently reported to be attacked by fungal pathogens, along with cellar spiders and sheet web spiders. Together these three families accounted for more than 40% of all reported cases of fungal parasitism in spiders.⁷ In North America specifically, free-living cursorial hunters like jumping spiders were the most frequently fungus-infected group.⁷

Winter dormancy likely increases vulnerability to fungi. A spider sitting motionless in a damp retreat for months is an ideal substrate for a slow-growing fungal infection. The spider’s immune system is presumably running at a reduced level during dormancy, and the cool, moist conditions inside leaf litter or beneath bark are exactly the environment many fungi thrive in. The review concluded that spider-pathogenic fungi are an important mortality factor that has been underestimated in ecological studies.⁷

Starvation is another risk. Jumping spiders do not eat during true dormancy, so they enter winter carrying the energy reserves they built up during autumn. If autumn prey was scarce, or if winter stretches on longer than usual, some spiders may simply run out of fuel before spring arrives. Dehydration in dry winter conditions can also be lethal, which is another reason why microsite humidity matters so much in their autumn real-estate search.

What Happens in Spring

As temperatures climb and day length increases in spring, jumping spiders emerge from their retreats and resume activity. The transition is not instantaneous. Spiders probably need a stretch of consistently warmer days before they can ramp their metabolism back up, begin moving, and start hunting effectively. Early spring is a vulnerable time: prey insects are also just beginning to reappear, so food may be scarce right when the spider’s energy reserves are at their lowest.

For species that overwinter as subadults, spring emergence marks the beginning of a final round of growth and molting before they reach sexual maturity. Mating typically follows shortly after, which is why you tend to start seeing bold, conspicuously colored adult jumping spiders actively displaying on sunny surfaces in late spring and early summer. The elaborate courtship dances and leg-waving displays that make jumping spiders so popular on social media are largely a warm-season phenomenon, driven by the timing of maturation after winter dormancy.

Species with two-year life cycles, like the sand-dwelling Yllenus arenarius, emerge from their second winter as mated adults. Their eggs will develop and hatch during the warm months, producing a new generation of spiderlings that must then survive their own first winter as tiny juveniles, starting the cycle over again.³

Jumping Spiders Found Indoors During Winter

If you find a jumping spider on your wall in January, it likely entered in autumn seeking a protected hibernation site and was roused by indoor heating. Heated homes present a confusing situation for a spider that expected to be dormant. The warmth kicks its metabolism back up, making it active and hungry at a time when there is very little prey available indoors. These spiders are generally not thriving inside your house. They are awake when they should not be, burning through energy reserves without a reliable food source.

The best thing you can do if you find one is either leave it alone in a cool, undisturbed area of the house, like a garage or basement, where it can settle back into low-activity dormancy, or gently relocate it to an outdoor spot with good shelter, such as a wood pile or a dense patch of leaf litter. Tossing it into open snow is likely fatal. Placing it somewhere with insulation from the worst cold gives it a reasonable chance of re-entering dormancy and surviving until spring.

Some tropical and subtropical jumping spider species, like Hasarius adansoni, have established permanent indoor populations in temperate regions. These spiders are not hibernating; they are genuinely living indoors year-round because they cannot survive outdoor winters in colder climates. If you find a small, dark jumping spider with distinctive markings living in your bathroom in midwinter and it seems perfectly healthy and active, it may be one of these synanthropic species that has adapted to human buildings as a permanent habitat rather than a seasonal refuge.

Climate Change and Shifting Winter Dynamics

Warming winters are likely reshaping the overwintering experience for jumping spiders in ways that researchers are only beginning to understand. Milder average temperatures sound like good news for a freeze-avoidant animal, and in some respects they are: fewer nights dipping below supercooling points means fewer lethal cold events. But the picture is more complicated. Warmer winters often come with reduced snow cover, which removes the insulating layer that buffers ground-level microsites from extreme cold snaps. A mid-winter warm spell followed by a sudden plunge can be more dangerous than a consistently cold winter with steady snow cover, because the spider may partially rouse from dormancy during the warm spell, burning precious energy, only to face a hard freeze without adequate protection.

Wolf spider research has shown that cryoprotectant levels accumulated during winter, while present, were modest enough that extreme cold events could still be lethal.⁵ If jumping spiders accumulate cryoprotectants at similarly modest levels, then unpredictable temperature swings during an otherwise mild winter could pose a real threat. The spiders may not invest as heavily in cold-hardening during a warm autumn, leaving them less prepared if a brutal cold snap arrives in February. Whether northern jumping spider populations can adjust their cold-hardening responses quickly enough to track shifting winter patterns remains an open question, and one that geographic variation in supercooling points suggests evolution can address over many generations but perhaps not within the span of a few unusually erratic winters.

1
Physiological Entomology. Winter ecology of spiders (Araneida)
2
PubMed Central. Microhabitat Selection for Overwintering: Overwintering Conditions of Three Jumping Spiders (Pellenes tripunctatus, P. nigrociliatus, and Attulus penicillatus) Living in Terrestrial Shells in the Czech Republic
3
BioOne (The Journal of Arachnology). THE LIFE HISTORY OF YLLENUS ARENARIUS (ARANEAE, SALTICIDAE)—EVIDENCE FOR SYMPATRIC POPULATIONS ISOLATED BY THE YEAR OF MATURATION
4
The Journal of Arachnology. Cold tolerance strategy, supercooling, and cold hardening in three populations of the jumping spider Phidippus audax (Araneae: Salticidae)
5
PubMed. Energy balance and metabolic changes in an overwintering wolf spider, Schizocosa stridulans
6
PubMed Central. Low temperatures impact species distributions of jumping spiders across a desert elevational cline
7
bioRxiv. Diversity of spider families parasitized by fungal pathogens: a global review