Thinking about keeping a tarantula, a colony of isopods, or a stick insect and not sure where to start? You’re in the right place — practical answers, honest picks, no fluff, built for people who actually keep these animals.
Invertebrate keeping is one of the fastest-growing corners of the pet world, and for good reason. Many species are quiet, take up very little space, and don’t need daily walks or constant attention. But “low maintenance” doesn’t mean “no maintenance” — invertebrates have precise husbandry needs, and getting the basics wrong is the single biggest reason new keepers lose animals in the first year.
What Counts as a Pet Invertebrate?
The category is broader than most people expect. It includes:
- Tarantulas — by far the most popular pet invertebrate, with hundreds of species varying wildly in temperament and care difficulty.
- Scorpions — hardy, long-lived, and generally easier to keep than people assume.
- Isopods (roly-polies) — increasingly popular as low-effort “cleanup crew” pets and bioactive enclosure additions.
- Millipedes — gentle, slow-moving detritivores that do well in humid bioactive setups.
- Stick and leaf insects — plant-eating, visually striking, and a great entry point for kids under supervision.
- Ant colonies (formicariums) — a niche but growing hobby built around watching colony behavior over time.
- Hermit crabs — technically crustaceans, often grouped with invertebrates, with their own specific humidity and molting needs.
Why People Keep Them
The appeal is real and specific: minimal noise, minimal odor when housed correctly, small footprint, and — for many species — a lifespan measured in years rather than months. Female tarantulas of some species can live 15-20+ years, which is a genuine long-term commitment people don’t always expect going in.
The Four Pillars of Invertebrate Care
Every species is different, but care always comes down to the same four fundamentals — covered in depth in our category guides below.
- Enclosure setup — the right size, substrate depth, and hides for the species’ natural behavior (burrowing vs. arboreal vs. terrestrial).
- Temperature & humidity — the single most common point of failure for new keepers. Most invertebrate deaths trace back to an enclosure that’s too dry, too wet, or swinging between extremes.
- Feeding — appropriately sized prey or plant matter on a schedule that matches the animal’s actual metabolism, not a guess.
- Handling — for many species, the honest answer is “as little as possible.” Handling is for the keeper’s benefit, not the animal’s, and it carries real risk for both of you with some species.
Good Beginner Species
If you’re just starting out, look at animals known for being forgiving of small mistakes: Chilean rose tarantulas and similar hardy terrestrial species, isopod colonies (genuinely hard to get wrong once set up), and stick insects. Skip fast, defensive, or highly venomous species until you’ve got a season of experience under your belt.
Mistakes New Keepers Make
- Misting on a fixed schedule instead of watching the actual substrate and adjusting.
- Buying an enclosure that’s too large for a young or small animal, making food genuinely hard to find.
- Handling a defensive species because it “seems calm” on a given day.
- Skipping quarantine when adding new animals to an existing collection.
Before You Bring One Home
Check your local and state regulations — a handful of invertebrate species are restricted or require permits in some regions. And never release a captive-bred invertebrate outdoors, even a “harmless” one; it’s bad for local ecosystems and, in many places, illegal.
Ready to go deeper? Our guides below cover feeding, health signs, choosing a species, and the gear that actually matters.
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Frequently Asked Questions
Most commonly kept tarantula species have mild venom comparable to a bee sting at worst, and the bigger practical risk is actually the urticating hairs some New World species flick when stressed, which can irritate skin and eyes. Choosing a calm, well-documented beginner species and minimizing handling reduces the risk to nearly zero.
Most invertebrate keepers never see an exotics vet — there's little a general vet can do for an invertebrate, and most issues are husbandry-related and fixed by adjusting the enclosure. A small number of exotics-specialist vets do exist for serious cases like injury or suspected parasites.
Less than most new keepers assume. Many terrestrial tarantulas do best in an enclosure only slightly larger than their leg span — oversized enclosures can actually make it harder for the animal to find food and feel secure.
Yes, as long as the enclosure is secure and out of reach of curious cats or dogs. The bigger risk usually runs the other way — a startled pet knocking over or damaging the enclosure — so stable, enclosed setups are worth the extra care.
Incorrect humidity is the single most common cause, followed by inappropriate enclosure size and skipping quarantine when introducing new animals. Getting the environment right solves most problems before they start.