Feeding a tarantula is the simplest job on this site and the one with the most ways to worry unnecessarily. There is no supplement routine, no salad, no schedule that has to be kept, and a healthy adult can refuse food for weeks without anything being wrong. What there is instead is a short list of feeders, a sizing rule, and one genuinely dangerous situation that catches new keepers. This guide covers all three. It is general husbandry, not veterinary advice.
What a tarantula eats, and what it does not need
Tarantulas are predators of live invertebrates. In captivity that means feeder insects, and essentially nothing else. There is no plant component, no prepared diet, and no reason to offer vertebrate prey to a pet tarantula, whatever the name "birdeater" suggests.
The part that surprises people coming from reptiles is that the supplement routine disappears. Tarantulas are invertebrates eating whole invertebrates, so the calcium problem that dominates lizard and amphibian feeding does not apply in the same way. There is no dusting step.
Gut loading is still worth doing, for a simpler reason: a feeder that has been fed properly is a larger, better-hydrated meal than one that has been sitting in a bare tub. The benefit is to the size and quality of the prey rather than to a mineral balance.
A shallow water dish matters more than most keepers expect and is part of feeding rather than separate from it, particularly for terrestrial species.
Which feeders work
Roaches
Feeder roaches are the standard choice for most keepers with more than one or two spiders. They are meatier per insect than a cricket, they cannot climb smooth surfaces, they are quiet, and they keep for a long time in a storage tub without much attention. That last point matters here more than anywhere: an adult tarantula eats infrequently, so feeders spend far more time in your care than in the enclosure.
Crickets
Crickets are the traditional feeder and remain the easiest to buy in a fine range of sizes, which is useful for spiderlings. They move a lot, which triggers a strike reliably. Against that, they are short-lived in storage, they smell, and they are the feeder most likely to injure a tarantula that cannot defend itself. That is not an argument against crickets. It is an argument for taking uneaten ones out.
We do not sell crickets. Dubia roaches are what we sell instead.
Mealworms and superworms
Most of the worm feeders are useful in a different way. They do not run, they can be offered in a shallow dish, and they can be pre-killed easily, which makes them the practical option for spiderlings and for a spider you do not want to leave live prey with. Superworms are large enough that sizing needs attention. Mealworms will burrow into substrate and vanish, so they are usually better offered on a dish.
Spiderlings
Very small spiderlings need very small prey. Flightless fruit flies, pinhead crickets, small roach nymphs, or a pre-killed piece of a larger feeder are all in normal use. Pre-killed prey is common practice at this stage precisely because a sling is small enough for a live cricket to be a real threat.
Sizing prey to the spider
Two versions of the sizing rule circulate in the hobby, and they broadly agree:
- Nothing larger than the tarantula's abdomen.
- Prey around one third to one half of the spider's body length.
Both are conventions rather than measured thresholds. Neither is about the spider's ability to subdue prey, which is considerable. They are about not putting a large, struggling insect in a small enclosure with an animal that may not be in a position to deal with it. Erring small costs nothing.
Two smaller feeders are almost always a better choice than one large one. It is also worth remembering that size names are not standardized between suppliers, so a measurement is more use than the words on the tub. For roaches, the dubia roach size chart gives the length in inches behind each size name.
How often, and why a fasting tarantula is usually fine
Tarantulas have slow metabolisms and no fixed feeding schedule. Published hobby guidance clusters around something like this, with wide variation by species:
| Stage | Typical interval | What actually decides it |
|---|---|---|
| Spiderlings | Every few days | Rapid growth. They molt often and eat more consistently. |
| Juveniles | Roughly weekly | Abdomen condition and whether the spider is still taking food. |
| Adults | Every one to two weeks, often less | Species, temperature, sex, and whether it is in premolt. |
Refusing food is normal in this animal in a way it is not in a lizard. Adults can go weeks or months without eating, and some species are known in the hobby for long fasts with no obvious cause. A spider that is refusing food but sitting normally, with a reasonably full abdomen and a full water dish, is usually a spider in premolt or a spider that is simply not hungry.
The signs that are worth attention are a shriveled abdomen, a hunched or curled posture, or a spider that has stopped moving normally. Those are not a feeding problem to be solved with more crickets, and an experienced keeper or a vet who sees invertebrates is the right next step.
Molting is when live prey becomes dangerous
This is the section that matters most.
A tarantula molting is completely defenseless. It lies on its back or its side, immobile, with a soft new exoskeleton and soft fangs. A cricket in the enclosure at that point is not prey. It is an insect chewing on a helpless animal, and it can kill it.
The practical rules:
- Never leave live prey in with a tarantula in premolt or mid-molt. If a feeder is not taken within a few hours, remove it.
- Learn the premolt signs. A darkened patch on the abdomen, a refusal to eat, increased webbing and reduced activity are the common ones.
- Do not disturb a molting spider, and do not try to help.
- Wait after the molt. The new fangs are soft and pale, and harden over the following days. Hobby guidance suggests waiting on the order of days for a small spider and longer for a large adult, and checking that the fangs have darkened before offering food.
Those wait times vary between keepers and between species, and they are conventions rather than measurements. The principle behind them is not in dispute: a spider with soft fangs can damage them on hard prey.
What to avoid
- Wild-caught insects. Pesticide residue and parasites, with no way to inspect for either.
- Live prey left in unattended. A common and avoidable cause of injury in captive tarantulas, by keeper experience.
- Prey clearly over the sizing rule.
- Vertebrate prey. Unnecessary, messy, and it fouls a small enclosure quickly.
- Overfeeding. A tarantula does not lose abdominal mass except by molting, so an overfed spider stays overfed for a long time.
On the enclosure side, uneaten prey and leftover food boluses are what mold and mites grow on. This is why a lot of keepers run isopods or a wider clean-up crew in the substrate. They deal with the leftovers rather than the spider. We do not sell isopods or clean-up crews.
Ordering for an animal that eats fortnightly
The buying problem for tarantula keepers is the inverse of the one lizard keepers have. The animal eats very little, so almost all of what you buy has to stay alive in your care for weeks. That pushes the decision toward feeders that store well rather than feeders with the best nutritional profile, and it makes storage conditions the thing worth spending effort on.
Keepers with a collection rather than a single spider usually settle on roaches for exactly that reason, and the guide to dubia roach care covers keeping them alive between feeds. For one adult tarantula, buying a small quantity more often is more practical than a bulk order that mostly dies before it is used.
Of the feeders covered here, we sell dubia roaches, fruit flies, mealworms and superworms, all in the feeders collection. When a box lands, what to do when your feeders arrive covers the unpacking, which matters more when the feeders have to last a month.
This guide describes feeding a healthy spider. A tarantula in a hunched posture, leaking fluid, or that has been unable to complete a molt is in trouble, and that is a matter for someone with hands-on experience rather than a change of feeder.