In Minnesota, the family Colletidae includes two bee genera: Colletes and Hylaeus. These two genera are very different: Colletes are medium-sized and nest in the ground, and Hylaeus are very tiny and nest aboveground in pre-existing cavities and in plant stems. Colletes transport pollen externally on pollen-collecting hairs on their hind legs, whereas Hylaeus transport pollen internally (ingested and stored in their crop). Colletes have dense hairs particularly on the thorax; Hylaeus are nearly hairless and resemble small black mason wasps. With all these differences, there are a few common traits of this family that include a short bilobed or forked glossa (tongue), the absence of a pygidial plate, one subantennal suture, and solitary nests. Colletid bees provide liquid provisions (instead of the typical cake-like pollen provisions) for their larvae. Lying on their side in the liquid provisions, the larvae "swim or sidestroke" across the provisions as they feed.

For the species that occur in Minnesota, this family includes twenty-two pollen-collecting specialists (oligolectic bees). All but one species (Hylaeus sparsus) occur within the genus Colletes.