A Bee Story February 2026

Mining bees belong to a large family of native bees called Andrenidae (an-DREN-uh-dee). In Washington State, this family includes four genera: Andrena, Calliopsis, Panurginus, and Perdita. Together, they make up some of the most common—and most easily overlooked—native bees of early spring.

They vary widely in size. Some Perdita, often called Fairy bees, can be as small as a pinhead, while medium-sized Andrena are closer to the size of a honeybee. Mining bees are equally diverse in appearance. They may be black, brown, reddish, or even shiny metallic green, often with pale white, yellow, or orange hair bands on the abdomen. Here in Washington, they are most often brown or black, sometimes with a subtle metallic sheen. Andrenidae are generally hairy bees, and males frequently sport a fuzzy facial “moustache,” a helpful clue for identification.

So how can you tell if the bee you’re seeing is a mining bee? Timing is a big hint. These native bees are often the most common bees flying in late winter and early spring. Look for them on dandelions as early as March. Another giveaway is how they carry pollen. Mining bees collect pollen on their hind legs, which can make them look like they’re wearing bright yellow trousers—or pollen pantaloons. You may also see them sunning themselves on bare ground or rocks, warming up before flight like birds on a cool morning.

Most of a mining bee’s busy life happens underground. These native bees are ground nesters, and each female digs her own tunnel system, complete with brood cells stocked with pollen and nectar for her young. While each bee tends to her own nest, many species nest close together, forming large aggregations that resemble bustling underground communes. These nests are typically six to twelve inches deep and are most often found in bare or lightly vegetated soil.

Different genera use different strategies to protect their developing young. Andrena and Calliopsis females line their brood cells with a wax-like oil produced by the Dufour’s gland, which helps protect the provisions and larvae from moisture and fungi. Panurginus females use soil or saliva to waterproof their cells, while Perdita generally skips nest linings altogether—an efficient approach for bees adapted to desert-like environments.

Despite their abundance, mining bees are gentle and rarely sting. Females can sting if handled, but they are not aggressive and are far more interested in flowers and nest building than people. Large nesting areas may look dramatic, but they are temporary and usually fade within a few weeks.

Mining bees play an essential role in our ecosystems. Like some of the earliest pollinators of the year, these native bees are active in cool temperatures when few other bees are flying. Many early-blooming native plants, fruit trees, and spring flowers depend on mining bees to get the season started.

In your own yard, small volcano-shaped mounds of soil often mark the entrances to underground nests. Leaving some bare, undisturbed ground, especially in sunny areas, is one of the easiest ways to support these important pollinators.

Think of mining bees as the early-rising construction crew of the native bee world. While others are still waiting for warmer days, mining bees are already digging, stocking pantries, and raising the next generation—quietly doing important work beneath our feet.

-Anne Bulger, Friends of Ridgefield NWR Board Member, & OSU Master Melittology Lead Instructor for the RNWR