Yellowjacket and Hornet Nest Removal

Baltimore's rowhome stock creates two very different jobs, and the right one depends on where the colony sits. An aerial bald-faced hornet nest — the gray football-shaped paper nest — hangs in an open spot: a Roland Park hemlock, a Charles Village porch ceiling, the underside of a Canton roof deck. Those are treated and physically taken down, and the job usually ends there because wasps never reuse an old nest. A yellowjacket colony behind formstone, in a Federal Hill cornice return, or under a Hampden back-porch step is the harder job. The insects you see going in at the second-story roofline may be traveling several feet inside the wall cavity to a nest you cannot reach. That kind of colony needs a dust applied at the true entry point so returning foragers carry it in, then a wait of several days before the hole is sealed. Sealing first is the classic mistake — trapped yellowjackets look for a second exit, and in an attached house the second exit is often your neighbor's closet or your own kitchen ceiling.

Ground nests behave differently again. Yellowjackets in Baltimore commonly take over old rodent burrows, the gap under alley pavers, or loose soil along a mulch bed — the strip between a Locust Point patio and the fence line is a classic spot. Ground colonies are treated at the tunnel opening, usually in the early morning or after dusk when foragers are home, and the hole is then closed with soil or stone so nothing re-excavates it. If the nest sits within a few feet of a back gate, a shared alley trash pad, or a stoop where kids come and going, say so when you call; proximity changes how we stage the visit and when the area is safe to walk again.

Season drives everything here. Overwintered queens start small nests in April and May, colonies grow quietly through July, then peak in late August and September — which is exactly when Fells Point and Highlandtown calls spike, because thousands of workers are hunting sugar around alley cans, outdoor tables and recycling bins. Late-season colonies are the largest and the most defensive, and they are also the ones most likely to be found by a homeowner on a ladder. Baltimore's first hard frost kills the workers and the colony dies on its own, so a nest discovered in November in an unreachable tree is often better left alone than paid for. We will tell you that on site rather than sell you a treatment. What we will not skip is the exclusion step: rowhome soffits, chimney flashing, and gaps around Bolton Hill window casings that hosted a colony this year will host one next year unless the opening is closed.