Careful inspection of a bee's morphology, from its wing veins to its antennae, tongue and leg parts, is necessary to identify a bee's species with certainty, and it is usually only possible when using a microscope or hand lens for close inspection. There are a variety of entomology books available to help with the identification process, and online sites, such as BugGuide and Cornell University's Bee Health website, offer identification guides and experts who assist with identification.
Digital photography is frequently used to identify bee species. Photos can be submitted to BugGuide. So long as the pictures are in focus and all of the necessary parts of the bee are visible, bee and taxonomy experts can often identify a bee's species based on a digital picture.
To ascertain a bee's genus or species, people examine the insect's keys, meaning the characteristics found on a bee that eventually result in an accurate identification. Some important things to consider include the bee's behavior, its diet and habits, its method of reproduction and its social interactions. The type of nest that bees create is also critical to their identification.
With more than 20,000 recorded species of bees throughout the world, one way to differentiate between the species is to examine the level of social interactions. While some species are solitary, others such as honey bees and bumble bees are highly social.