In Denmark, there are a few hundred species of the so-called solitary bees. It is usually small, grayish or dark species. Most look like small versions of the honeybee. They are called solitary bees because they do not live in the colonies. Each female bee builds its own nest, lay eggs and gather food for the larvae by herself. Depending on the species, solitary bees can build nests in the ground, in plant stems, in holes in walls or in woodwork, and the nests can be built from different materials such as clay or plant parts.
When feeding the larvae, the bee fills the nest cells with pollen and nectar.
Solitary bees play a role in the pollination of many plants. They can sting, but they are not very aggressive, and since they do not have to defend a shared nest, there are no cases of mass attacks. Because solitary bees are often small, the stings are usually mild.
The Colletes davieseanus is a solitary bee that often lives in colonies. It can dig passageways to the nests in the loose mortar of houses. It rarely stings, but it can destroy the mortar.