Best Diet for Tarantulas: What Tarantulas Should Really Eat

Tarantulas are carnivorous ambush predators that do best on live invertebrate prey. In captivity, the safest routine diet is usually commercially raised feeder insects, especially crickets and roaches. Many pet parents also use mealworms, superworms, hornworms, or the occasional waxworm, but variety matters because no single feeder insect is ideal for every life stage.

For most species, prey size matters as much as prey type. A good rule is to offer insects that are about the size of the tarantula’s abdomen or smaller. Slings and juveniles often need pinhead or very small crickets, small roach nymphs, or cut-up prey if they are shy feeders. Adults can usually handle larger crickets or roaches, but oversized prey can stress the spider and may injure a tarantula during or after a molt.

Wild-caught insects are not a safe staple. They may carry pesticides, parasites, or residues from lawns and gardens. Fatty feeders like waxworms can be useful as occasional variety, but they should not make up the main diet. If your tarantula is a poor eater, newly molted, or showing changes in body condition, it is smart to check in with your vet before making major feeding changes.

Water still matters, even for species that get some moisture from prey. A shallow water dish is appropriate for most juveniles and adults, while very small slings may need moisture managed differently based on species and enclosure setup. Diet and hydration work together, so a tarantula that is eating poorly may also need a husbandry review with your vet.

There is no one feeding schedule that fits every tarantula. Species, age, enclosure temperature, molt cycle, and body condition all affect appetite. In general, slings are fed more often than adults because they are growing. Many slings do well with small prey every 2-5 days, juveniles every 4-7 days, and adults about every 7-14 days. Some adult tarantulas, especially slower-growing species, may eat less often and still be healthy.

A practical starting point is one appropriately sized prey item at a time, then adjust based on how your tarantula looks and behaves. If the abdomen becomes much larger than the carapace, feeding may be too frequent. If the abdomen looks shrunken, wrinkled, or the spider is losing condition, husbandry or health problems may be involved. Your vet can help sort out whether the issue is diet, dehydration, premolt, parasites, or another concern.

Do not leave live prey in the enclosure for long periods, especially with a tarantula that is in premolt or has recently molted. Uneaten insects can stress or injure a vulnerable spider. Many keepers remove uneaten prey within 12-24 hours, and sooner if the tarantula appears defensive, weak, or close to molting.

For budgeting, feeder insects for one tarantula often run about $5-$20 per month. Small slings may cost less, while large adults eating roaches or larger feeders may cost more. Buying feeder insects in bulk can lower the monthly cost range, but only if you can house and feed the insects properly.

A tarantula skipping a meal is not always an emergency. Many healthy tarantulas refuse food before a molt, during seasonal slowdowns, or after a recent large meal. What matters is the full picture: body condition, hydration, activity, posture, and whether the spider is otherwise acting normally.

Concerning signs include a very small or wrinkled abdomen, repeated refusal to eat outside of an obvious premolt period, trouble catching prey, weakness, abnormal posture, dragging legs, or difficulty righting itself. Moldy leftover prey, mites, foul enclosure conditions, and repeated prey attacks on the spider are also red flags that the feeding setup needs attention.

See your vet immediately if your tarantula is bleeding hemolymph, has been injured by prey, is stuck in a molt, cannot stand normally, or suddenly collapses. These are not routine feeding issues. They can become life-threatening quickly, especially in small or recently molted spiders.

If appetite changes last more than expected, bring your vet details about species, molt history, prey type, feeding frequency, enclosure temperatures, humidity, and water access. Those husbandry details often help explain why a tarantula is not eating well.

If your tarantula does not do well with one feeder insect, there are several reasonable options. Commercially raised crickets and roaches are usually the most practical staples. Roaches are often easier to digest for some keepers to manage, and they tend to be less noisy and less likely to die off quickly than crickets. Small mealworms or superworms can add variety, though they should not be the only food offered.

For tiny slings or picky feeders, smaller prey items are often safer than trying larger insects. Pre-killed or freshly crushed feeder insects may help some shy or delicate tarantulas start eating, especially if live prey seems overwhelming. This can be useful for slings, but feeding response varies by species and individual spider.

Avoid relying on wild insects, fireflies, pesticide-exposed bugs, or prey collected from garages, gardens, and bait shops unless you know they were raised specifically as feeders. These options carry more risk than benefit. Very fatty feeders, like waxworms, are better treated as occasional variety rather than a routine staple.

If your tarantula repeatedly refuses common feeders, your vet may recommend reviewing enclosure setup, molt timing, hydration, and prey size before changing the whole diet. In many cases, the issue is not the insect itself but the husbandry around feeding.