Bees do not eat grass, as their diet is strictly herbivorous and specialized to consume only resources derived from flowers. The simple answer to why you might see a bee interacting with a blade of grass is that the insect is looking for something other than food. Bees are dependent entirely on flowering plants for their nutritional needs, meaning they cannot digest the cellulose and other components that make up grass.
The Bee Diet Blueprint
A bee’s entire life cycle is fueled by two primary floral resources: nectar and pollen. Nectar, converted into honey, serves as the colony’s sole source of carbohydrates, providing the necessary energy for flight, heating, and all metabolic processes. An adult worker bee requires a steady source of sugar, with some species needing approximately 11 milligrams of dry sugar daily for basic maintenance.
Pollen is the source of all other necessary nutrients, including protein, lipids, vitamins, and minerals. Bees mix pollen with glandular secretions and nectar to create a fermented product known as “bee bread,” which is the primary food for developing larvae and newly emerged adults. Rearing a single worker larva is a protein-intensive process, estimated to require 124 to 145 milligrams of pollen.
The quality of this pollen is highly variable across plant species, which affects bee health significantly. Pollen must contain a minimum of 20 to 25 percent crude protein to adequately meet the colony’s dietary requirements for optimal development. When high-quality floral sources are scarce, bees must sometimes collect less nutritious pollen, such as that from wind-pollinated plants, to survive until better forage is available.
Why Bees Are Near Grass
Bees often visit grassy areas not to feed, but to collect water, which is a constant requirement for colony maintenance. They will seek out dew drops and moisture sitting on grass blades, especially during hot weather, for hydration and to regulate the temperature inside the hive through evaporative cooling.
The presence of bees on grass can sometimes be attributed to the collection of wind-blown pollen. Grasses are wind-pollinated, meaning they do not produce nectar or bright colors to attract insects, but they do produce large quantities of pollen. While this pollen is a poor nutritional substitute for flower pollen, bees may collect it when preferred floral sources are extremely limited.
Other instances of bees interacting with lawns relate to shelter and nesting, particularly for solitary species. Many native bees are ground-nesting, and they require bare or lightly vegetated soil within a grassy area to dig their nests.
The Impact of Lawns on Bee Health
Modern, highly maintained lawns pose significant environmental challenges to bee populations, primarily by eliminating their food sources. A dense monoculture of turfgrass, kept short by frequent mowing, prevents the growth of flowering plants like clover and dandelions. These “weeds” are often the only source of early-season nectar and pollen available to emerging bee species in suburban and urban environments.
The widespread use of pesticides, especially systemic insecticides, on lawns presents a direct threat to bee health. These chemicals are absorbed by the entire plant, and when bees collect the low-quality pollen from flowering grasses during times of scarcity, they can ingest the contaminated material.
A large, uniformly green lawn contributes to habitat fragmentation, creating a biological desert that forces bees to travel further between food sources.
Research shows that simply reducing the frequency of mowing, such as changing from weekly to biweekly, allows lawn flowers to bloom, significantly increasing the abundance of bees. Allowing a few common “weeds” to grow provides a simple, immediate way to turn a featureless lawn into a valuable, temporary foraging habitat.