How Long Can Jumping Spiders Go Without Food?

A healthy adult jumping spider can survive roughly two to four weeks without a meal, though the exact duration depends on species, body size, temperature, and whether water is available. That range gives pet owners some breathing room during vacations and reassures anyone who has watched their spider refuse food for days on end. But the picture gets more complicated with younger spiders, varying environmental conditions, and the surprisingly dramatic behavioral shifts that hunger triggers in these small predators.

Why the Range Varies So Much

Jumping spiders belong to the family Salticidae, the largest spider family on earth, with more than 6,000 described species. A bold jumping spider (Phidippus audax) the size of a grape is going to burn through its energy reserves at a different rate than a tiny zebra spider (Salticus scenicus) that could sit on a pencil eraser. Larger-bodied species carry proportionally more stored lipids and proteins in their abdomens, which acts as a built-in pantry. That is why a well-fed adult Phidippus with a plump, round abdomen can outlast a recently molted juvenile of the same species by a significant margin.

Temperature plays an equally important role. Spiders are ectotherms, meaning their metabolic rate rises and falls with the surrounding temperature. A jumping spider kept in a warm room burns through its reserves faster than one in a cooler environment. In the wild, spiders that experience cooler nights naturally slow their metabolism during those hours, stretching their energy budget. In heated homes where temperatures stay above 24°C around the clock, a pet jumping spider’s internal clock essentially runs faster, and food needs increase accordingly.

Water Matters More Than Food

If you are worried about your jumping spider skipping meals, the real concern should be hydration. Spiders lose moisture through respiration and through their book lungs, and dehydration can kill a jumping spider in a matter of days even when it has plenty of fat reserves left. A spider that has access to a light misting or small water droplets on the walls of its enclosure can survive far longer without prey than a spider in a dry container. Many spider keepers who leave town for a week or two report their spiders doing fine without food, provided they left a lightly dampened surface or a small damp cotton ball in the enclosure before departing.

You can often spot dehydration before starvation becomes an issue. A dehydrated jumping spider’s abdomen looks shriveled and wrinkled, and the spider becomes lethargic. A starving spider also develops a shrunken abdomen, but the progression is slower and the spider tends to remain alert and active, actively hunting, until it reaches a critical point. If you notice a shriveled abdomen combined with lethargy, water is the priority.

How Hunger Changes Their Behavior

Jumping spiders do not just passively wait out hunger. Their behavior shifts in ways researchers have documented across multiple species. One field study of a diurnal jumping spider found something counterintuitive: although the species is active during the day, the majority of individuals observed in the field were actually staying inside their silk nests rather than foraging. The spiders remaining in their nests turned out to be more starved than those observed actively moving around outside.

That finding seems paradoxical at first. Why would a hungry spider stay hidden instead of going out to find food? One explanation is energy conservation. A spider that is already running low on reserves may not have the metabolic budget to sustain an active foraging bout, especially in conditions where prey density is low. Staying in a silk retreat and waiting for conditions to improve, or for prey to wander closer, can be a more energy-efficient strategy than roaming. Jumping spiders are visual hunters that rely on quick bursts of speed and precise leaps, all of which require energy. A severely depleted spider may lack the power to execute a successful pounce, making foraging a risky investment with a poor chance of return.

Pet owners sometimes see this play out in their enclosures. A spider that has gone a week or more without eating may become less active and spend more time tucked into its web sac. This is not necessarily a sign that the spider is sick. It may simply be conserving energy, and offering a small prey item at that point usually triggers an immediate feeding response.

Aggression, Mating, and the Cost of Being Hungry

Hunger does not just change where jumping spiders spend their time. It also changes how they interact with other spiders, sometimes dramatically. Research on female jumping spiders found that food-deprived females displayed higher levels of aggressive behavior and were more likely to engage in pre-copulatory sexual cannibalism, where the female kills the male before mating even begins. These same food-deprived females had lower mating success overall compared to well-fed individuals.²

From the female’s perspective, this makes a certain cold-blooded sense. A male spider represents a meal, and if you are starving, the caloric value of eating a potential mate may outweigh the reproductive benefit of mating with him. For breeders who keep jumping spiders in captivity, this is a practical concern. Introducing a male to a hungry female significantly raises the risk that the male ends up as food rather than a father. The standard advice in the jumping spider keeping community, to make sure both spiders are well-fed before pairing them, has solid behavioral research behind it.

Spiderlings and Juveniles Are More Vulnerable

The two-to-four-week window for fasting tolerance applies mainly to healthy adults. Spiderlings, the tiny hatchlings that emerge from egg sacs, are far more sensitive to food deprivation. Their small bodies carry minimal energy reserves, and they have higher surface-area-to-volume ratios, which means they lose moisture faster. A spiderling that goes more than a few days without eating can die or fail to molt successfully.

Molting is the critical bottleneck. Juvenile jumping spiders go through multiple molts as they grow, and each molt requires a substantial investment of energy and specific nutrients. A spider that enters a molt cycle in poor nutritional condition may get stuck partway through, a condition keepers call a “bad molt.” The spider either dies during the process or emerges deformed, often with legs that did not fully extend. For this reason, juvenile jumping spiders should be fed more frequently than adults, ideally every two to three days, to keep them in good condition ahead of their next molt.

The difference in resilience between juveniles and adults is large enough that the feeding advice for each life stage looks entirely different. An adult bold jumping spider can comfortably eat two or three appropriately sized prey items per week. A growing spiderling of the same species may need food every other day. Missing a feeding for a spiderling is a bigger deal than missing one for an adult, and keepers raising spiders from egg sacs learn quickly that the tiny ones need consistent attention.

How They Burn Through Their Reserves

Spiders store energy primarily as lipids in their abdomens, and the abdomen’s size is a visible indicator of nutritional status. A well-fed jumping spider has a round, almost glossy abdomen. As the spider burns through its fat stores during a fast, the abdomen visibly shrinks, becoming more wrinkled and less taut. This external cue is one of the most reliable ways to gauge whether your spider needs food.

During prolonged fasting, spiders shift from burning readily available lipids to breaking down proteins, including muscle tissue. This is the point where things become dangerous. A spider that has depleted its fat reserves and is now catabolizing protein is in serious trouble and may not recover even if food is offered. The transition is not visible from the outside, which is why the safest practice is to never let a spider’s abdomen get severely shrunken. If the abdomen is noticeably smaller than the cephalothorax (the front body segment), it is past time to feed.

Why Jumping Spiders Refuse Food

One of the most common worries for new jumping spider owners is a spider that simply will not eat. Before assuming something is wrong, consider the most common reasons for food refusal, most of which are harmless.

Pre-molt: Jumping spiders typically stop eating for several days before a molt. Their body is preparing to shed its exoskeleton, and the digestive system partially shuts down. This can last anywhere from a few days to over a week, and it is completely normal.
Overfeeding: A spider with a very full abdomen may simply not be hungry. Jumping spiders are opportunistic feeders in the wild, but in captivity where food is abundant, they sometimes just take a break.
Low temperatures: If your room is cold, the spider’s metabolism slows and its appetite drops. This is especially common in winter for keepers who do not supplement with heat.
Prey preference: Some individual spiders are picky. A spider that refuses mealworms might pounce immediately on a fruit fly, and vice versa. Offering a different prey type often solves the problem.
End of life: Jumping spiders live roughly one to three years depending on species and sex. A spider approaching the end of its lifespan will gradually eat less and become less active. There is unfortunately not much to be done in this case.

Pre-molt refusal is the one that causes the most unnecessary panic. A keeper who does not recognize the signs, the spider becoming less active, sometimes appearing slightly duller in color, and building a thicker-than-usual web sac, might try to force-feed or excessively handle the spider during a vulnerable period. The best response to a spider that has stopped eating but still looks healthy is to leave it alone, keep humidity appropriate, and check on it daily.

Practical Feeding Guidelines for Pet Jumping Spiders

If you keep a jumping spider as a pet, a simple feeding schedule handles most situations. Adults of common pet species like Phidippus regius or Phidippus audax do well with two to three feedings per week. Each meal should be a single prey item roughly the size of the spider’s abdomen, or slightly smaller. Fruit flies work for smaller species, while larger species can take small crickets, bottle flies, or mealworms.

Overfeeding is a real risk in captivity and arguably more common than underfeeding. A spider that is offered food daily may gorge itself to the point where its abdomen becomes dangerously distended. While spiders do not become obese in the mammalian sense, an overstuffed abdomen is more prone to rupture from even a minor fall, and these spiders climb constantly. A moderate feeding schedule with occasional skipped days mimics the natural feast-and-famine rhythm that wild jumping spiders experience and tends to produce healthier, longer-lived captive animals.

For short absences of a week or so, a healthy adult spider with a reasonably full abdomen and access to water droplets will be fine. For longer absences of two weeks or more, you are pushing into the range where some risk develops, especially if the enclosure dries out. If you travel frequently and keep jumping spiders, investing in a small misting system or asking someone to add a few water droplets every few days is a better safeguard than worrying about feeding.

Wild Jumping Spiders and Natural Fasting Cycles

In the wild, jumping spiders do not eat on a predictable schedule. Their meals depend on prey availability, weather, season, and competition. A spider living on a sun-warmed fence post in summer might catch several small insects per day. The same spider in early spring, when insect activity is low, might go a week or more between meals. This irregular feeding pattern is what their physiology evolved around, which is why captive spiders tolerate meal gaps so well.

Seasonal changes also influence feeding patterns in temperate climates. Many jumping spider species in northern latitudes overwinter as juveniles or subadults, spending months in a state of reduced activity tucked inside silk retreats under bark or in leaf litter. During this period their metabolic rate drops substantially, and they survive entirely on stored reserves without eating at all. This overwintering fast can last several months, far exceeding the weeks-long tolerance of an active summer spider, because the cold-induced metabolic slowdown dramatically reduces their energy expenditure.

Life history strategies also differ between males and females in some jumping spider species, with immature males and females sometimes showing different body parameters and behavioral patterns that reflect different energy allocation priorities.³ Males of many species tend to be smaller and shorter-lived, investing more energy in searching for mates than in building up fat stores, while females prioritize body condition because they need substantial reserves to produce eggs. A well-fed female preparing for egg production may have an abdomen nearly twice the size of a male’s, and her fasting tolerance reflects that larger reserve.

When Fasting Becomes a Medical Concern

For most keepers, occasional fasting is normal and nothing to worry about. But there are scenarios where a spider’s refusal to eat signals something genuinely wrong. If a spider has not eaten in more than two weeks, is not in pre-molt (no thickened web sac, no dulled coloring), and shows a visibly shrunken abdomen, something may be off. Possible culprits include parasitic infections, mite infestations, or exposure to pesticides or cleaning chemicals that have contaminated the enclosure.

Mites are a particular concern for captive spiders. Grain mites can hitch a ride into an enclosure on feeder insects, and while they do not directly attack the spider, a heavy mite infestation stresses the animal and can lead to feeding refusal. If you see tiny white or tan dots moving around the substrate or on the spider’s body, mites are likely the issue. Cleaning the enclosure thoroughly, replacing the substrate, and sourcing feeders from a different supplier usually resolves the problem.

Pesticide exposure is harder to diagnose but worth considering if your spider suddenly stops eating after you have used household insecticides, plug-in repellents, or even heavily scented cleaning products near the enclosure. Spiders are arthropods, and most insecticides are designed to kill arthropods. Even residual fumes from a spray used in an adjacent room can be enough to sicken or kill a small spider. If you keep jumping spiders, treating the room they live in with any insecticide is a risk, and the symptoms often look like simple feeding refusal before the spider deteriorates further.