The Masked Bees are slender and black in color. They can grow up to 10 mm in size. These bees in this species have a pale marking on faces for which they got the name. Many bees in the same species have a distinctive yellow spot on their thorax. The masked bees have a low amount of hair and carry the pollens by swallowing it. They build their nests in existing holes in woods or pithy stems. They build their nests using cellophane-like secretion.