These do look like wasps, though it's hard to tell exactly which kind as hundreds of species live in our area. Their size and body shape suggests a type of paper wasp, of which several species occur in Maryland. Our Social Wasps web page provides information about these and other colony-nesting wasps, including management options if a nest is causing problems by risking stings when they feel threatened by people.

If a nest has not been located, not much can be done, since wasp sprays are intended to be applied directly to a nest (or if inaccessible directly, onto/into its entrance hole in the ground or behind a wall or in a tree cavity). The chemicals used in those sprays are not wasp-specific, and may harm other insects (bees, ladybugs, fireflies, etc.) that wander over spray residues, so their use should ideally be limited to only treating a wasp nest itself. The linked page above does describe where paper wasp nests tend to be constructed; they are not nearly as large in size as yellowjacket or hornet nests can become by summer's end.

Like other social wasps, paper wasps can be defensive of a nest and sting if they feel it is threatened by someone getting too close, or if individual wasps feel threatened by being swatted. Otherwise, they tend to leave people alone, as they are mostly concerned with finding food (flower nectar for adults, and insects like caterpillars, aphids, etc. for their young back in the nest). In gardens, they are considered beneficial because they pollinate flowers and hunt insects that we tend to consider pests.

Miri