When the animal hosts leave or die, the bat bugs invade living areas through cracks and crevices. Bed bugs that can develop solely on human hosts are primarily moved from one location to the next via infested furniture and bedding. Bed bugs and bat bugs also may come from other infested homes by way of water pipes, gutters, through windows, along walls, etc. Migrations may occur if a house is vacated and their food supply is cut off. A closely related species, most commonly found in higher elevations of the state, is the swallow bug.
Swallow bugs develop on nesting swallows, normally cliff swallows.
However, barn swallows also can support these Insects. Problems with human bites occur when birds nest on the sides of buildings. Swallow bugs breed freely all summer in swallow nests. In early autumn, when bird migration occurs, the swallow bugs scatter in search of new hosts and invade human dwellings. They also increase their activity in spring, coinciding with the return of the swallow hosts.