Jumping Spider Feeding: Schedule, Diet, and Why They Stop Eating

Jumping spiders eat live insects only: flightless fruit flies for spiderlings, then small crickets, houseflies, bluebottle flies and small roach nymphs as they grow. How often comes down to the abdomen, which tells you more than any calendar does. Here's a schedule by life stage, what to feed, and how to read one that's stopped eating.

Feeding Schedule by Life Stage

• Spiderlings (1st to 3rd instar): Fed most often, generally every 1 to 2 days on 1 to 2 flightless fruit flies, and one breeder recommendation goes further, to daily small feedings at this stage.
• Small to mid juveniles: Every 2 to 3 days, stepping up to larger fruit flies, then pinhead crickets or small houseflies.
• Sub-adults: Every 2 to 4 days. Avoid overfeeding right before the final molt, a distended abdomen raises rupture risk during that molt.
• Adults: Every 2 to 5 days, with the abdomen deciding where in that window a given spider sits. Males in particular are sometimes fed as infrequently as every 10 days. Gravid, egg-guarding females may eat more often or refuse food almost entirely during guarding, and either is normal individual variation.

The rule underneath all of it: offer food rather than force a schedule, and let the abdomen guide you. A shrunken or wrinkled abdomen means it's hungry and can be fed early. A plump, rounded abdomen noticeably wider than the cephalothorax means skip the next feeding. Feed in the morning, jumping spiders are visual daytime hunters, and pull uneaten live prey within a few hours to overnight so it doesn't harass or injure the spider, especially near a molt.

What Jumping Spiders Eat

An obligate carnivore, no plant matter and no commercial spider food. Flightless fruit flies are the staple for slings and small juveniles. Pinhead-to-small crickets, houseflies, and bluebottle or greenbottle flies work for juveniles through adults, flies in particular are a preferred, low-injury-risk staple since they can't bite back or burrow. Small dubia roach nymphs are another low-risk option. Mealworms and waxworms work as occasional treats rather than staples, waxworms especially are high in fat and best used sparingly, some keepers save them for a post-molt energy boost.

Bluebottle flies are often bought as fly spikes, the larvae, which keep in the fridge for a week or more and hatch into flies within a few days at room temperature. A short spell in the fridge slows a fresh fly enough to drop it into the enclosure without the rest escaping.

That diet mirrors what they catch in the wild. Jumping spiders stalk and pounce rather than build webs, and they take whatever small insects they can overpower. A field study of one species, Menemerus taeniatus, found flies and moths made up about two thirds of everything it caught.

Keep prey noticeably smaller than the spider: about half its body length, three quarters at the most, matched to the size of the chelicerae. Oversized prey is the most repeated safety warning here, a cricket that's too big can injure or kill a jumping spider, especially near a molt.

Gut-load feeder insects on a nutritious diet, pureed carrot, apple, or a sugar-yeast mix for fruit fly cultures, for a day or two before offering them, so the spider gets those nutrients secondhand. This matters most for breeding or gravid females. For hydration, use a shallow water dish and take the drinking droplets off the same misting the enclosure already gets every 2 to 3 days, never mist the spider's abdomen directly, water can seep between the book-lung plates and cause suffocation.

Safe and Unsafe Prey

Safe: flightless fruit flies, pinhead-to-small crickets, houseflies, bluebottle and greenbottle flies, small dubia roach nymphs, gut-loaded mealworms, and waxworms as an occasional treat.

Never feed: ants, repeatedly named as the single most important thing to avoid, they can bite or spray formic acid, and jumping spiders show an instinctive fear response to them. Hard-shelled beetles and pill bugs, too tough to bite through effectively. Fireflies. Other spiders, a real cannibalism and injury risk. Wild-caught or unknown insects, especially anything from an area treated with pesticides. And any prey bigger than the spider's abdomen, an injury risk regardless of species.

Why Jumping Spiders Stop Eating

1. Premolt fasting. Commonly stops eating days to weeks before shedding, windows vary widely, from a few days for spiderlings up to a few weeks for larger juveniles and sub-adults. Don't force-feed or leave live prey in during this window.
2. Post-molt recovery. New fangs are soft right after shedding and can't safely bite or digest prey. Wait about 2 to 3 days before offering food again.
3. Breeding and egg-guarding. Courting adults, and especially females guarding an egg sac, can eat noticeably more or less than usual, either direction is considered normal.
4. Environmental stress. Temperatures too cool, low humidity, recent rehousing, or excessive handling can trigger refusal outside of a molting window.
5. Old age. Older adults, particularly past their final molt, naturally slow their feeding pace, sometimes fasting a week or more, occasionally up to a month, without indicating illness.
6. Prey pickiness. Individual spiders can be selective, preferring flies over crickets or vice versa, and may ignore a feeder they simply don't want even while healthy.
7. Dehydration or illness. Refusal paired with a shrunken, raisin-like abdomen, lethargy, poor jumping ability, or curled-inward legs points to a real problem, not a normal fasting phase.

When to Worry

None of this is veterinary-established, it is hobbyist-reported, which is worth knowing going in. A healthy adult can safely go roughly 2 to 3 weeks without eating, and older adults are anecdotally reported tolerating a month or more, particularly around a molt or egg-guarding, none of that alone is cause for alarm. Spiderlings have much smaller reserves and shouldn't be left that long, keep offering appropriately sized food every couple of days at that stage even if it's sometimes refused.

Real reasons for concern: food refusal running well past two weeks with no molt ever occurring, no interest in food for a week or more after a molt has already completed, a visibly shrunken or wrinkled abdomen especially paired with lethargy, legs curling inward or an inability to right itself if flipped, visible injury or fluid leakage, and a failed or stuck molt, a spider partially out of its old exoskeleton with no progress for several hours. These last few are treated as urgent, warranting an exotic-animal vet rather than a wait-and-see approach. Few vets treat spiders, so it pays to know which one near you will before any of this happens.

Spiders can't be dusted with supplement powder, which makes what the feeders ate the only nutrition that reaches them, so gut-loading the feeders is the whole supplement routine.

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Sources & Further Reading