When insects swarm around a backyard barbecue or picnic, hovering over meat, the common assumption is that these striped visitors are bees. This observation often leads to confusion, as bees are generally known for their diligent collection of nectar and pollen. The attraction to protein, specifically meat, is a behavior that belongs to a different group of social insects, which is often misidentified. Clarifying this case of mistaken identity explains why certain insects are so determined to claim a share of your outdoor meal.
Identifying the Scavenger: Bees Versus Wasps
The insect most commonly seen scavenging for meat at picnics is not a bee, but a social wasp, such as a yellow jacket or hornet. These two groups, while related and sharing black and yellow coloration, have distinct differences in physical appearance and diet. Bees have a rounder, more robust body covered in fine, branched hairs, giving them a fuzzy look that aids in pollen collection.
In contrast, social wasps possess a slender, smooth body with a much narrower “waist” connecting the thorax and abdomen. Their bodies are nearly hairless and appear shiny. The fundamental difference lies in their primary food source: bees are herbivores subsisting on nectar and pollen, while wasps are opportunistic omnivores. This omnivorous diet allows social wasps to seek both sugary substances for energy and protein sources for feeding their young, which is the key to their attraction to meat.
The Essential Protein Needs of the Colony
The biological drive behind a wasp’s attraction to meat is rooted entirely in the nutritional requirements of its developing young. Adult worker wasps, like bees, primarily use simple carbohydrates like nectar for their own immediate energy needs. However, the growing larval stage requires a significant amount of protein and amino acids to fuel their rapid growth and metamorphosis into adult wasps.
The adult worker wasps serve as hunters and scavengers, relentlessly collecting protein from sources that include other insects, spiders, and human food scraps like meat. Once captured, the protein is chewed and processed into a digestible paste that is then delivered back to the nest and fed directly to the larvae. This diligent delivery of protein ensures the colony’s successful expansion throughout the summer months.
The relationship between the adult wasps and the larvae is symbiotic, known as trophallaxis, where food is exchanged within the colony. In return for the protein-rich food the workers provide, the larvae secrete a tiny droplet of sugary fluid that the adult wasps consume. This sugar secretion provides the workers with a steady source of carbohydrates to fuel their demanding foraging flights. The need for meat is therefore not for the adult’s diet, but for the continued production of this sugary internal fuel source from the growing brood.
The Seasonal Shift in Foraging Behavior
The scavenging behavior becomes most noticeable and aggressive during the late summer and early fall because the internal dynamics of the colony change dramatically. As the season progresses, the queen wasp shifts her focus and stops laying new worker eggs, instead producing the new generation of queens and male drones. Eventually, the final batch of larvae matures, pupates, and no longer requires the constant supply of protein that the workers have been providing.
When the larvae stop producing their sugary secretion, the adult worker wasps are suddenly cut off from their primary carbohydrate source. They are left with high energy demands but no internal sugar supply, and the colony’s social structure begins to break down. This shift causes the workers to become frantic and highly visible as they search for alternative external sources of sugar to sustain themselves.
The newly “unemployed” workers turn their attention to any readily available source of carbohydrates, which includes ripe fruit, spilled sodas, and any sweet human food. While they are primarily seeking sugar at this stage, they remain opportunistic and will still investigate human food, including the remnants of a barbecue, leading to the aggressive swarming observed at outdoor gatherings. This late-season desperation for quick energy transforms the diligent summer hunter into the persistent autumn nuisance.