Grassland rewilding is creating habitat for billions of invertebrates whose welfare may be positively affected by habitat restoration, with emerging science informing the welfare dimensions.
Grassland rewilding welfare involves the largely unexplored territory of invertebrate welfare at population scale. As scientific evidence for invertebrate sentience and pain capacity grows - with bees, cockroaches, and other insects showing increasingly compelling signs of welfare-relevant states - the welfare implications of habitat changes affecting billions of individual invertebrates become ethically significant. Grassland restoration dramatically increases invertebrate abundance, creating conditions where more individuals can fulfil behavioural needs including foraging, mating, and thermoregulation. The alternative - intensively farmed monoculture grassland treated with pesticides - is associated with invertebrate population collapses that affect individual welfare through food scarcity, chemical sub-lethal effects, and habitat inadequacy. Whether the welfare benefit to individual invertebrates in restored grassland is morally significant depends on contested questions about invertebrate sentience, but the precautionary principle argues for habitat management that benefits rather than harms the populations of potentially sentient animals in greatest numbers. Grassland rewilding also has indirect welfare benefits for vertebrate species that depend on invertebrate prey.