Invertebrates
Tarantulas, scorpions and hermit crabs.
Species in this group
3About invertebrate pets
Invertebrate pets — tarantulas, scorpions, and hermit crabs — are quiet, low-space, and surprisingly long-lived companions. Female tarantulas can live 20-30 years, hermit crabs 15-30 years in proper conditions, and scorpions 6-25 years depending on species. Their aging is slow and largely hidden — molting is the main outward life-stage marker. Knowing their age in human-equivalent years helps you anticipate molting cycles, breeding maturity, and senior-stage husbandry.
Lifespan range in this group
Aggregated from individual species in this group. Indoor, well-cared-for animals typically reach the upper end.
Common care tips for invertebrate pets
- Maintain species-correct humidity and temperature — desert tarantulas need 50% humidity, tropical species 70-80%.
- Provide a deep substrate for burrowing species; arboreal tarantulas need vertical climbing space.
- Never handle during pre-molt; tarantulas and scorpions are vulnerable for days before and after molting.
- For hermit crabs: provide deep substrate (3x crab height), saltwater pool, and multiple shells of varying sizes.
- Watch for failed molts, dehydration, and parasite mites; pet stores often sell crabs in poor condition needing rehab.
FAQ
How long do pet invertebrates live?
Female tarantulas 20-30 years, males 5-7 years. Hermit crabs 15-30 years with proper care. Scorpions 6-25 years depending on species.
Why do female tarantulas live so much longer than males?
Once mature, male tarantulas stop molting and die within 1-2 years. Females continue molting and reproducing for decades, with some old-world species exceeding 30 years.
Are tarantulas dangerous?
Most pet tarantulas have mild venom — comparable to a bee sting. Old-world species (e.g. baboon, earth tiger) have stronger venom; choose New World species for beginners.
How do I know my tarantula's age?
Estimate via leg span, molting frequency (juveniles molt every few months, adults annually), and species growth charts. Calculate human-equivalent age to plan handling and care.
Do hermit crabs really live 30 years?
In the wild, yes. In captivity, most die within 1-2 years due to small tanks, lack of saltwater, and missing shell variety. Properly kept hermit crabs commonly reach 15+ years.