Gardens and farms host enormous populations of invertebrates including earthworms, beetles, and spiders whose welfare may be significantly affected by common land management practices including pesticide use, rotary cultivation, and soil compaction.
Garden and farming invertebrates occupy the frontier of welfare consideration — their sentience is uncertain, their numbers are vast, and the practices that affect them are ubiquitous. The welfare-relevant question is whether mechanical injury, chemical exposure, and habitat destruction cause suffering to individual earthworms and insects in any morally meaningful sense. Current evidence suggests earthworms have nociceptors and respond to damage with behavioural changes consistent with pain, though the subjective experience question remains open. Given this uncertainty, a precautionary approach counsels minimising unnecessary harm: no-till practices, pesticide reduction, and habitat provision are justified by both ecological benefit and potential welfare benefit. The scale consideration is also relevant: practices causing widespread invertebrate mortality in agriculture affect billions of individuals even at probabilities of sentience far below certainty.