Honey bee colony collapse disorder and broader pollinator decline involve welfare questions of staggering scale as billions of individual bees experience the stresses of pesticide exposure, habitat loss, and pathogen pressure.
The welfare question of honey bees hinges on whether they are sentient - whether they experience something analogous to suffering. Research suggests bees may have primitive emotional states: bees show pessimistic cognitive bias after negative experiences, analogous to a pessimistic mood state in vertebrates. If bees can suffer, then the billions exposed to sublethal neonicotinoid doses that impair their navigation and cause them to become lost away from the hive may be experiencing something like distress. Varroa mite parasitism weakens individual bees physically. The collapse of colonies leaves surviving workers without the social structure and communication networks their biology depends on. The scale of honey bee mortality - billions of individuals annually - makes this a welfare issue of extraordinary magnitude even at very low probabilities of individual sentience.