Two of the subfamilies, Euryglossinae and Hylaeinae, lack the external pollen-carrying apparatus (the scopa) that otherwise characterizes most bees, and instead carry the pollen in their crops.

These groups, and most genera in this family, have liquid or semiliquid pollen masses on which the larvae develop.

They can be found all over the world, but the most species live in South America and Australia.

[5] The Colletidae are one of the four bee families that contain some crepuscular species (of both the "vespertine" and "matinal" types).

These bees, as is typical in such cases, have greatly enlarged ocelli.