Why do yellow jackets carry off their dead?

Yellow jackets carry off their dead as part of hygienic behavior called necrophoresis, which is common in social insects like ants, bees, and wasps, where dead individuals are removed from nest to maintain colony hygiene, prevent disease spread, and keep nest clean. When a yellow jacket dies inside nest or nearby, workers detect chemicals released by dead body, such as oleic acid, that signal death, and they carry dead wasp away from nest and drop it outside, sometimes carrying it some distance to prevent pathogens, fungi, and bacteria that could grow on corpse and infect colony, especially larvae and queen. This behavior helps prevent spread of disease and keeps nest sanitary, as crowded nests with many individuals are vulnerable to infection. Yellow jackets may also carry off dead to avoid attracting predators that are attracted to dead insects. This hygienic behavior is important for colony survival, as social insect colonies with thousands of individuals living closely need cleanliness. So yellow jackets carry off their dead not for mourning or ritual, but for hygiene and disease prevention, as part of colony maintenance, similar to ants that carry dead ants to refuse pile, and this behavior is instinctive, not emotional, though it appears purposeful.