Silk production kills billions of silkworm pupae annually by boiling cocoons to preserve the continuous silk thread. The welfare status of silkworms is uncertain but warrants consideration.
Silkworm welfare sits at the far end of moral uncertainty in animal ethics. The evidence for insect sentience generally is weak, and silkworms — highly domesticated, with simple nervous systems — are among the less plausible candidates for morally relevant experience. Yet the scale of killing involved (billions annually) means that even a small probability of morally relevant suffering would aggregate to significant concern. Peace silk addresses the killing method but not the domestication and confinement conditions. For those who apply strong precautionary principles to moral uncertainty, avoiding conventional silk is defensible. For those who weight certainty of sentience heavily before applying moral concern, silkworm welfare may fall below their threshold for action.