Pet Invertebrates: Tarantulas, Scorpions, and Millipedes Care Guide

Pet invertebrates are some of the most underrated animals in the hobby. Tarantulas, scorpions, and millipedes all live for years (sometimes decades), require minimal space, and offer fascinating natural behaviors most pet owners never experience. They're also dramatically different from one another in care requirements — and grouping them under "invertebrates" obscures the species-specific knowledge needed to keep each successfully. This guide covers the practical care fundamentals for the three most common pet invertebrate groups.

Tarantulas

Tarantulas are the most popular pet invertebrates in North America. With dozens of species in the trade ranging from beginner-friendly to advanced-keeper, they offer a long-lifespan (5–25+ years for females) commitment with minimal daily maintenance.

Beginner-friendly species

• Chilean rose hair (Grammostola rosea): 4–5 in legspan, slow-moving, docile, lives 15–25+ years
• Pink-toed tarantula (Avicularia avicularia): arboreal species, 4–5 in, generally calm
• Mexican red knee (Brachypelma hamorii): striking colors, calm, 5–6 in
• Curly hair (Tliltocatl albopilosus): hardy, eats reliably, 5–6 in

Tarantula enclosure

Adult terrestrial tarantulas need a roughly square enclosure 2–3× the spider's legspan in floor dimensions. Arboreal species need taller enclosures with vertical climbing space. Substrate should be 2–4 inches of moisture-retentive material (coconut fiber, vermiculite mix). Provide a shallow water dish.

Temperature and humidity

Most pet tarantulas thrive at 70–80°F with 60–75% humidity. Tropical species need slightly higher humidity; arid species (desert hair tarantulas) tolerate drier conditions. Tarantulas don't need supplemental heat in normal indoor conditions.

Feeding

Tarantulas eat insects exclusively in captivity. Common feeders:

• Discoid roaches or crickets — 1–2× per week for adults
• Superworms — occasional treat (high fat)
• Hornworms — occasional, valuable for hydration

Adult tarantulas eat infrequently — every 1–2 weeks is normal. Skip feedings for 4–6 weeks before molt; tarantulas refuse food during the pre-molt phase. Keep feeding schedule slow rather than fast.

Handling — generally don't

Most tarantulas tolerate handling, but the practice is discouraged for several reasons: a fall from waist height can rupture an abdomen and kill a tarantula. Some species have urticating hairs that cause skin irritation. Old World species (anything from Africa or Asia) have stronger venom than New World species — they can cause significant medical reactions in some people. As a general rule: tarantulas are display animals, not interactive pets.

Scorpions

Pet scorpions are venomous, nocturnal arachnids that thrive in dry to humid conditions depending on species. Like tarantulas, they offer long lifespans (4–25+ years) and minimal daily maintenance.

Beginner-friendly species

• Emperor scorpion (Pandinus imperator): 6–8 in, the largest pet species, mild venom (similar to bee sting), tropical humid conditions
• Asian forest scorpion (Heterometrus spp.): 4–6 in, similar to emperor in care, slightly cheaper
• Desert hairy scorpion (Hadrurus arizonensis): 5 in, US native, arid conditions, more defensive

Scorpion enclosure

Emperor and forest scorpions need a 10–20 gallon enclosure with deep substrate (4–6 inches) for burrowing. Use coconut fiber, organic topsoil, or a mix. Provide cork bark and rotting wood for hiding spots. Maintain 70–80% humidity and 78–82°F warm side.

Desert species need shallower substrate (2 inches), drier conditions (30–40% humidity), and higher daytime temperatures (85–95°F basking).

Venom considerations

Beginner-friendly pet scorpions have venom comparable to a bee sting in most people — uncomfortable but not dangerous to healthy adults. People with allergies, especially to bee or wasp stings, should be cautious. Avoid the more-venomous species (deathstalker, fat-tailed scorpions) as a beginner — they have potentially lethal venom.

Feeding scorpions

Same feeders as tarantulas — crickets, roaches, occasional larger feeders. Frequency: 1–2× per week for adults. Like tarantulas, they eat infrequently and refuse food before molting.

African giant millipedes

African giant millipedes (Archispirostreptus gigas) are gentle, slow-moving, herbivorous detritivores that grow 8–10 inches long and live 5–10 years. They're an excellent introductory invertebrate for keepers wanting something calm and tactile.

Enclosure

10–20 gallon enclosure with at least 6 inches of substrate — millipedes burrow extensively. Substrate should be:

• Coconut fiber + organic topsoil + rotting hardwood (oak preferred)
• Calcium source mixed in (crushed cuttlebone)
• Dark, kept consistently moist

Top with leaf litter (oak or maple, pesticide-free). Maintain 70–80°F and 70–80% humidity.

Diet

Millipedes eat decomposing plant matter, fruits, and vegetables:

• Cucumber, zucchini, lettuce, apple, mango, banana — small portions, replaced before mold
• Decomposing leaf litter (this is their primary natural food)
• Calcium supplementation: cuttlebone in substrate or dusted greens 2× weekly

Avoid citrus (acidic) and onion family. They eat slowly — single piece of fruit can last days.

Handling

Millipedes handle well — they're slow, harmless, and tolerate gentle interaction. Wash hands thoroughly before AND after handling. They secrete a mild defensive chemical (benzoquinones) when stressed that can stain skin and cause mild irritation in sensitive people. Never let a millipede near your face — the chemical can cause significant eye irritation.

Common across all three groups

Invertebrate care fundamentals that apply broadly:

• Pesticide-free feeders only: wild-caught insects can carry pesticides that kill invertebrates
• Clean water source: shallow dish, fresh water, replaced frequently
• Quiet location: invertebrates are stress-prone; vibration and constant disturbance reduce lifespan
• Don't keep multiple individuals together: cannibalism is common in tarantulas and scorpions; millipedes can overcrowd
• Pre-molt fasting is normal: tarantulas and scorpions refuse food for weeks before molting; this is not illness

Bottom line

Pet tarantulas, scorpions, and millipedes are dramatically different animals despite all being invertebrates. Choose by what kind of pet you actually want — tarantulas for long-lived display, scorpions for nocturnal observation, millipedes for gentle handling. Each requires species-specific husbandry; broad "invertebrate care" advice misses what matters. For more on exotic pet keeping, see our Creature Insights blog.

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