Burrowing bees are solitary, ground-nesting bees that dig tunnels in soil to lay their eggs. They belong to several different bee families, and roughly 70% of all bee species worldwide nest underground. Despite the alarm they can cause when dozens emerge from a lawn in spring, these bees are docile, rarely sting, and play a critical role in pollinating both wildflowers and food crops.
Common Types of Burrowing Bees
Several bee families nest underground, and they vary widely in size and appearance. Mining bees (family Andrenidae) are among the most frequently encountered. They’re slightly smaller than honeybees, typically black with reddish hair on the thorax and sometimes the abdomen. Sweat bees (family Halictidae) are usually tiny and black, though some have a greenish or coppery metallic sheen. They’re the only ground-nesting bees that sometimes form small social colonies rather than nesting alone.
Membrane bees (family Colletidae) are slender and easy to confuse with mining bees. Melittid bees (family Melittidae) are small and black, and also look similar. Leafcutter bees (family Megachilidae) are larger, solitary bees that sometimes nest in the ground as well, though they’re better known for nesting in cavities. Across all these families, burrowing bees can come in surprising colors: blue, green, copper, or metallic reddish-brown depending on the species.
What Their Nests Look Like
A burrowing bee nest starts as a small hole in the ground, typically about a quarter inch wide. Each hole belongs to a single female. Below the surface, she digs out a network of tunnels leading to brood chambers, the tiny cells where her offspring will develop. Most brood cells sit between 6 and 16 inches below the surface, though some species that reuse existing nests have tunnels extending dozens of feet underground.
The excavated soil has to go somewhere. Some bees simply push it to the surface, creating a small mound around the entrance that looks a bit like an ant hill. Others are more elaborate builders. The sunflower specialist bee Diadasia enavata, for example, piles removed soil into small towers called tumuli that can reach a few inches tall before toppling over.
Inside the tunnels, different species line their brood cells with different materials. Leafcutter bees cut neat circles from leaves to partition their cells, sometimes using flower petals to create nests that look almost decorative. Mason bees gather mud. Wool-carder bees scrape soft hairs from plant stems to form their nest walls. These linings protect the developing larvae from moisture, fungi, and soil pathogens.
Seasonal Activity and Life Cycle
The most visible burst of burrowing bee activity typically happens in March or early spring, when dozens to hundreds of bees emerge from the ground after developing underground as larvae the previous year. The timing shifts depending on your climate and the species involved, but the pattern is consistent: adults emerge, mate, and the females immediately get to work collecting pollen to provision new underground cells where they lay eggs.
The entire adult phase is brief. Most burrowing bees are active for only a few weeks. After the female finishes provisioning and sealing her brood cells, the adults die. The larvae develop underground through summer and fall, overwintering in their cells before emerging the following spring to repeat the cycle. This short window of activity is one reason burrowing bees catch people off guard. They seem to appear suddenly, buzzing low over the lawn in large numbers, then vanish just as quickly.
Are Burrowing Bees Dangerous?
Burrowing bees are not aggressive and do not defend their nests the way social insects like yellowjackets do. Female burrowing bees can sting, but they rarely do unless physically handled or stepped on. Males, which are often the more visible ones buzzing energetically over nesting areas as they search for mates, lack a stinger entirely. They’re completely harmless despite looking busy and territorial.
Because of this temperament, burrowing bees are not considered a significant medical threat. You can walk across a lawn dotted with nest holes without provoking a sting. Children, pets, and bare feet are generally safe, though basic awareness is still sensible during the few weeks the bees are active.
How to Tell Them Apart From Yellowjackets
This distinction matters. Yellowjackets also nest underground, but they are aggressive, colonial, and will sting repeatedly to defend their nest. A few key differences make identification straightforward.
- Entrance size: A burrowing bee nest has a single small hole, roughly a quarter inch across. A yellowjacket colony entrance is noticeably larger.
- Traffic pattern: Only one bee enters and exits each burrowing bee hole. A yellowjacket nest will have a steady stream of wasps coming and going from a single, shared entrance.
- Body type: Burrowing bees have fuzzy, hairy bodies. Yellowjackets are smooth and shiny with distinct yellow-and-black banding.
- Behavior: Burrowing bees want to fly away from you. Yellowjackets will hover near their entrance and pursue perceived threats.
If you’re unsure, watch from a safe distance for a minute. A cluster of individual holes with bees calmly moving in and out points to ground-nesting bees. A single larger hole with aggressive wasps circling it is likely a yellowjacket colony, and that one warrants caution.
Why They Matter for Pollination
Native bees, including ground-nesting species, pollinate an estimated 80% of flowering plants worldwide. In the United States, bees of all types pollinate roughly 75% of the fruits, nuts, and vegetables grown commercially. That adds up to more than $15 billion in increased crop value each year, according to the USDA. One out of every four bites of food you eat exists because of bee pollination.
Burrowing bees are especially efficient pollinators for early-spring crops and native wildflowers because they emerge when many other pollinators are still dormant. Some species are specialists, visiting only a narrow range of plants, which makes them irreplaceable for those particular species’ reproduction. Their underground nesting also contributes to soil health. The tunnels function as natural aeration holes, improving the penetration of water and nutrients into compacted soil.
Living With Burrowing Bees in Your Yard
Because burrowing bees are active for only a few weeks and pose almost no sting risk, the simplest approach is to leave them alone. Their nest holes do not damage grass or soil. Once the nesting season ends, rain washes the excavated soil back into place and the holes disappear completely.
If the bees have chosen an inconvenient spot, like a high-traffic walkway or a play area, you can relocate them without pesticides. Ground-nesting bees strongly prefer dry soil. Simply running a sprinkler over the nesting area will encourage them to move elsewhere. If they return to the same patch of lawn year after year, watering that area before they emerge in early spring will redirect them to drier ground before they even start digging.
Thick, healthy turf also naturally discourages nesting because bees prefer bare or thin patches of soil where digging is easier. Overseeding sparse areas and maintaining consistent soil moisture through the spring are the most effective long-term deterrents. Pesticides are unnecessary, and using them eliminates pollinators that are actively benefiting your garden and local ecosystem.