How I finally stopped watching my jumping spider starve
The problem isn't that jumping spiders don't eat. It's that most people buy them already half-starved from bad sourcing, then wonder why their Phidippus audax won't touch a cricket for three weeks. I've kept them for a while now across several species. Jumping spiders are ambush hunters, not scavengers. They have to see prey move to trigger the strike response. Put a dead fly in there and they'll walk past it like it's invisible. That's the first thing people get wrong, and it costs lives.
The Jumping Spider Feeding Guide Most People Skip
Here's how feeding actually works in practice. Use fruit flies (Drosophila) for juveniles and small adults under two centimeters. Pinheads or newly hatched crickets work too, but fruit flies are cheaper and easier to keep a colony going. For anything larger than 2cm, use pinhead crickets, small roaches, or larger fruit flies. Never feed full-sized crickets to a small spider. The cricket will fight back, and jumping spiders are lightweight. One bite to the abdomen and you've lost your spider. The frequency depends on species and size. Most Phidippus species eat every two to three days when actively molting or in prime adult stage. Adult males that have matured stop eating much at all and live off stored energy for their final mating attempts. I've seen males survive ten days without food after their final molt without issue. Females, especially gravid ones, will eat daily if food is available. Here's what nobody tells you about freezing prey. Thawed frozen fruit flies are fine for juveniles, but adult jumping spiders often reject them. The smell dissipates quickly once thawed, and these spiders rely heavily on chemical cues. My workaround was keeping a small fruit fly colony in the same enclosure as the spider during feeding time. Live prey stays active, triggers the chase instinct, and the spider actually engages instead of ignoring the offering.
Another thing people miss: humidity affects appetite more than temperature. If your enclosure runs dry below sixty percent relative humidity, the spider's metabolism slows and feeding drops off. I learned this the hard way when my female P. regius stopped eating during a dry winter. She wasn't ill. The air was just too dry. Bumped humidity up and she resumed eating within a day.
Get the Full Details
What to feed and what to avoid
Fruit flies are the baseline. Houseflies are fine occasionally but can carry mites. Pinkie mice are absolutely not appropriate for jumping spiders regardless of size claims online. I've seen people try it and just make a mess that breeds mold inside the enclosure within forty-eight hours. Supplements aren't really necessary if you're feeding a varied diet of appropriately sized live prey. Dusting gut-loaded insects with calcium is standard practice in the herpetoculture world and translates fine here, but most keepers skip it without issues. The spider gets what it needs from the prey itself. The one scenario where this approach completely fails is with spiders that have recently molted. A freshly molted jumping spider is soft, pale, and completely inactive for three to five days. During this window, do not introduce any prey. The spider cannot defend itself and the prey will attack instead. I've watched keepers drop a cricket next to a fresh molt and then panic when the cricket starts climbing the spider's leg. It's not aggression. The spider is helpless.
Keep feeding records. Write down what you fed and when. It sounds excessive until you're trying to figure out whether a twenty-day gap in eating is normal for that individual or a sign something is wrong. Most jumping spider deaths from starvation happen because people assume the spider is "just having a slow week" when it actually stopped eating after its previous molt and nobody connected the dots.
