Most bee species worldwide are strictly diurnal, meaning they are active only during daylight hours, but their collective behavior shifts dramatically once the sun begins to set. As light levels decrease, foraging and pollination cease, giving way to rest, maintenance, and preparation for the next day. Where a bee spends the night depends entirely on whether it belongs to a communal colony or lives an independent existence.
The Social Bee Answer: Retreat to the Colony
Social bees, such as honeybees and bumblebees, utilize their communal structure as a nighttime sanctuary, relying on the warmth and protection of the hive or nest. Once inside, the colony remains a hub of activity focused on internal functions, even as the day’s foraging ceases.
Older worker bees often settle into a sleep-like state, a period of rest characterized by antennae stillness and a relaxed posture, which can last five to eight hours. Other colony members focus on essential maintenance tasks that do not require external light. This includes the crucial work of processing collected nectar into honey by fanning their wings to evaporate excess moisture.
Thermoregulation is a major nighttime responsibility, as bees must maintain a consistent temperature inside the hive to protect the developing brood. When temperatures drop, bees form a tight cluster and shiver their flight muscles to generate heat. If the temperature rises too high, they fan the air to circulate and cool the interior, while guard bees defend the entrance against potential intruders.
The Solitary Bee Answer: Resting Outdoors
The vast majority of bee species are solitary, lacking a communal hive or complex social structure, meaning their nighttime routines are far more exposed and individual. Solitary female bees typically retreat to their individual nests, which may be located in small cavities, hollow plant stems, or soil burrows. They shelter there overnight to protect their developing brood cells.
Solitary male bees, who have no nest to maintain, often rest completely exposed to the elements. They seek out sheltered spots on vegetation, such as clinging to grass stalks or resting within the protective folds of closed flowers. Many male bees exhibit a unique behavior of clustering together on a plant stem, gripping the edge of a leaf or stalk with their mandibles and hanging motionless until dawn.
Why Bees Stop Flying at Night
The sudden cessation of flight at dusk is driven by environmental and biological limitations that make nighttime activity inefficient and hazardous. Bees rely heavily on the sun and the patterns of polarized light for navigation, using these cues as a compass between foraging sites and their homes. Without this solar reference point, their complex visual system is ineffective for long-distance travel, making them easily disoriented.
The drop in temperature after sundown is the second limiting factor. Bees are ectotherms, relying on external heat, and must warm their flight muscles to a specific temperature—typically above 53°F (12°C)—to generate the power needed for flight. Cooler nighttime air prevents them from maintaining this muscle temperature, forcing them to remain grounded to conserve energy.
The Rare Exception: Truly Nocturnal Bees
While the vast majority of bees are strictly daytime flyers, a small number of specialized species, primarily in tropical and arid regions, have evolved to be active in low-light conditions. These truly nocturnal or crepuscular bees, including some sweat bees and carpenter bees, have developed physical adaptations that enhance navigation in the dark.
The most notable adaptation is the significant enlargement of the three simple eyes, known as ocelli, located on the top of the head. These enlarged ocelli function like light-gathering lenses, increasing the bee’s sensitivity to low-intensity ambient light. This allows them to forage for nectar and pollen on flowers that only open at night, exploiting a resource niche unavailable to their daytime counterparts.