Yellow jackets are social wasps known for their black and yellow markings. They live in organized colonies with a queen, workers, and males. While insects don’t “sleep” like humans, yellow jackets have periods of activity and inactivity linked to environmental factors and their life cycle. Their behavior shifts from daily routines to seasonal patterns, managing their energy and survival.
Yellow Jacket Daily Rhythms
Worker yellow jackets are active during daylight hours. Throughout the day, these wasps perform tasks for colony maintenance and growth. Their activities include foraging for food, such as sugars from nectar and fruits, and proteins from other insects, meat, or fish to feed developing larvae. They also engage in nest building, expanding the paper-like structure from chewed wood fibers mixed with saliva.
As dusk approaches and temperatures drop, foraging yellow jacket activity decreases significantly. They return to their nests, found underground, in tree cavities, or within structures. This return to the nest and inactivity is their equivalent of resting or “going to sleep,” as they remain inactive overnight. Their poor night vision means they reduce aggression unless disturbed.
The Annual Colony Cycle
Yellow jacket colonies are annual, lasting from spring to late fall. A new colony begins in spring when a single queen emerges, builds a small nest, and lays eggs. As initial eggs hatch, the queen nurtures the first generation of sterile female workers. These workers then take over nest expansion, foraging for food, and caring for subsequent larvae, allowing the queen to focus solely on egg-laying.
The colony grows rapidly throughout the summer, reaching peak sizes of several thousand workers, sometimes up to 5,000, by late summer or early fall. During this period, the nest expands significantly, sometimes reaching the size of a basketball. As fall progresses, the colony’s focus shifts from producing workers to creating new queens and male drones. With colder temperatures and dwindling food sources, the original queen, worker yellow jackets, and male drones die. The entire established colony perishes.
How Queens Survive Winter
While worker yellow jackets and male drones perish with the first hard frosts, newly produced, fertilized queens are the only colony members to survive winter. These queens enter diapause, a state of metabolic inactivity adapted for cold months. During diapause, their metabolic rate lowers, conserving energy.
To overwinter, these fertilized queens seek sheltered locations. Common sites include hollow logs, under loose tree bark, within leaf litter, in soil cavities, or inside human-made structures like attics and sheds. They tolerate freezing conditions by producing “antifreeze” proteins that prevent ice crystals from forming inside their bodies. When spring arrives and temperatures rise, these queens emerge from their dormant state, search for a suitable nesting site, and establish new colonies, completing the annual cycle.