Pesticide exposure — particularly neonicotinoids — causes sublethal neurological and behavioural harms in honey bees that reduce individual welfare and colony survival.
Neonicotinoid welfare harm operates below lethal thresholds: bees that are not killed outright suffer navigation impairment, reduced learning ability, and compromised waggle dance communication. A bee that cannot navigate home abandons foraging, weakening the colony and dying alone. The social harm extends beyond the individual — impaired forager communication reduces the colony's foraging efficiency, leading to food shortages that affect thousands of individuals. Sublethal but welfare-significant harm at this scale demands regulatory attention.