Spiders kept as pets raise welfare questions about whether arachnids have the capacity for suffering, and what minimum care standards should apply to invertebrate pets.
Spider welfare sits at the frontier of the expanding circle of moral concern. The evidence for rich subjective experience in spiders is weaker than for vertebrates, but spiders clearly show behavioral responses to harmful stimuli and have more complex nervous systems than previously thought. The pragmatic welfare case — that uncertain sentience combined with easily preventable suffering warrants minimum care standards — applies as much to arachnids as to insects. Wild collection is an additional concern, as it involves capture stress and high mortality. The pet trade in tarantulas would benefit from captive-breeding requirements and minimum housing standards.