The perception that a bee’s hair is “sticky” is not due to a glue-like substance, but rather a combination of physical structure and electrical forces that make pollen collection highly efficient. These specialized hairs, technically known as setae or pili, are fundamental to the bee’s survival and the reproduction of flowering plants. The bee’s body covering is an adaptation for foraging, allowing it to gather the protein-rich pollen needed to feed its young. A foraging bee can accumulate nearly a third of its own body weight in pollen during a single trip.
The Specialized Structure of Bee Hair
Unlike the smooth, single strands of human hair, most of a bee’s body is covered in branched hairs, known as plumose. Under a microscope, these hairs resemble tiny feathers or miniature bottle brushes. This branching morphology dramatically increases the surface area of the bee’s coat. The microscopic branches and hooks provide countless physical points of contact for pollen grains to lodge themselves.
Pollen grains that land on the bee’s body are immediately trapped in the angles between the main axis of the hair and its lateral barbs. This architecture functions like a mechanical sieve, ensuring that once a grain contacts the hair, it is physically held in place. This dense, branched coat covers the head, thorax, and abdomen, serving as the initial collection surface.
The Electrostatic Mechanism of Pollen Collection
The apparent “stickiness” is enhanced by the triboelectric effect, which is the generation of static electricity. As a bee flies, friction caused by rubbing against air molecules strips electrons from the surface. This leaves the insect with a net positive electrical charge.
The flowers a bee visits are grounded and often develop a negative electrical charge, which is transferred to the pollen. When the positively charged bee approaches a negatively charged flower, the electrical fields interact, creating a strong attractive force. This force is so powerful that pollen grains can literally “leap” from the flower’s anthers onto the bee’s body, sometimes without direct contact. This electrostatic attraction acts like an invisible magnet, making the hairs highly effective at collecting pollen.
Specialized Tools for Pollen Management
Once the pollen adheres to the hairs, the bee must consolidate it for transport back to the hive. The bee uses a specialized grooming routine to scrape the collected pollen from its body. This involves a series of brushes and combs located on the legs that work in a coordinated fashion. The forelegs and middle legs remove pollen from the head, eyes, and thorax, transferring it backward toward the hind legs.
The most specialized structure for transport is the corbicula, or pollen basket, found on the outer surface of the hind tibiae of species like honey bees. The bee uses stiff, rake-like hairs on its hind legs to scrape the pollen off the brushes of the opposite leg. The collected pollen is then mixed with nectar or regurgitated honey to moisten it, forming a cohesive mass. The presence of pollenkitt, a viscous, fatty substance coating pollen grains, further enhances adhesion. This moist pellet is then packed and compressed into the concave corbicula, held in place by long, curved hairs, ready for the flight home.