Earthworms are central to soil health and are used in enormous numbers in fishing and research. Their welfare is almost entirely unaddressed in regulation or practice.
Earthworm welfare sits at the frontier of moral consideration. Evidence for sentience is weaker than for vertebrates, but nociceptive responses and behavioural flexibility suggest some capacity for harm. The precautionary principle argues for minimising unnecessary earthworm suffering at scale. Reduced tillage, organic farming, and catch-and-release fishing practices all reduce earthworm harm.