The emerging field of insect welfare is beginning to apply welfare frameworks to the challenging annual migrations of monarch butterflies.
Applying welfare frameworks to monarch migration requires engaging seriously with insect sentience debates. The navigation challenge of migrating thousands of kilometers on a set of instincts rather than learned routes creates what is functionally a high-stakes survival challenge. Pesticide exposure that impairs flight and navigation potentially causes functional suffering analogous to a human with impaired coordination attempting a demanding physical task. The precautionary welfare principle applied to billions of individuals in an annual population that has declined catastrophically suggests that reducing pesticide exposure and providing adequate food resources during migration are welfare-positive interventions regardless of where the insect sentience debate ultimately settles.