Spring is the turning point in Maryland’s pest year. After a mild winter that rarely kills off overwintering populations, the warmth that arrives in March and April wakes everything up at once. Termites begin their swarm season, ants start foraging, and the stink bugs that spent the winter in your walls become active again. A few hours of prevention now, before the pressure builds, is the cheapest and most effective pest control there is.
Maryland’s spring is also wet, and that matters. The humid climate and the high soil moisture across the coastal plain feed the pests that will define the rest of the year. This checklist works through the house from the ground up.
Watch for termite swarms first
Termites are the defining pest threat in Maryland, and spring is when they show themselves. Subterranean termite swarm season runs from March through May, when winged reproductive termites, called swarmers, leave the colony to start new ones. A swarm is the single most visible sign of a termite problem, and it is easy to miss or misread.
Walk the inside and outside of your home and look for:
- Groups of winged insects around windows, doors, and light fixtures, often the first thing a homeowner notices
- Discarded wings, which swarmers shed in small piles on windowsills and floors
- Mud tubes, the pencil-width tunnels of soil that subterranean termites build up the foundation
- Wood that sounds hollow when tapped, or that crumbles when probed
Swarmers are often mistaken for flying ants. The quick difference: termite swarmers have a straight, even-width body, straight antennae, and four wings of equal length. Flying ants have a pinched waist, bent antennae, and front wings longer than the back. If you see a swarm, do not wait. Maryland’s heavy termite pressure means the colony is likely well established by the time it swarms. The termite inspection and treatment service page explains what an inspection covers, and the subterranean termite profile goes deeper.
Seal the exterior
Spring is the right time to close the gaps that pests use, before the summer surge of ants and the fall return of stink bugs and rodents. Walk the full perimeter of the house with a caulk gun and a notepad.
- Seal cracks in the foundation and the gaps where the foundation meets the framing.
- Caulk around every point where a pipe, cable, or utility line enters the house. These penetrations are reliable entry points for mice, ants, and roaches.
- Check the weatherstripping and door sweeps on every exterior door, including the garage. A gap under a door the width of a pencil is a mouse-sized opening.
- Inspect window screens for tears and repair them. Maryland’s long mosquito season makes intact screens worth the effort.
- Look at vents, dryer vents, attic vents, and crawl space vents, and make sure they are screened and intact.
In a Maryland crawlspace home, pay particular attention to the crawl space access door and vents, since the crawl space connects to wall voids that lead into the living space. In an older Baltimore rowhouse, the aging masonry has many small gaps, and a careful pass with sealant pays off.
Address moisture
Moisture is what drives Maryland’s worst pest problems. Subterranean termites, carpenter ants, camel crickets, and American cockroaches all favor damp conditions, and Maryland’s humid climate means moisture builds easily.
- Check the grading around the foundation. Soil should slope away from the house so water drains off rather than pooling against it.
- Clean gutters and downspouts so they carry roof water well away from the foundation. Clogged gutters that overflow against the wall create exactly the damp conditions termites and ants want.
- Inspect the crawl space for standing water, damp soil, and condensation. A persistently wet crawl space is an open invitation to termites and camel crickets. A vapor barrier and proper ventilation help.
- Fix leaking faucets, pipes, and hose bibs. A slow leak feeds a pest problem.
- Look at the basement for damp corners, condensation on pipes, and any musty smell.
Take care of the yard
The yard is where many pest problems start, and spring is the time to set it up well for the season.
- Move firewood, lumber, and any wood debris away from the house and up off the ground. Wood against the foundation is a direct bridge for termites and harborage for ants and rodents.
- Trim back shrubs, branches, and vines so they are not touching the house. Vegetation against the wall gives ants, spiders, and other pests a path indoors.
- Clear leaf litter and mulch back from the foundation. Damp mulch piled against the wall holds moisture and shelters insects. Keep a few inches of clearance.
- Remove standing water. Maryland’s mosquito season is long and intense, and it starts with the breeding sites available in spring. Empty or store buckets, planters, tarps, old tires, kiddie pools, and anything else that holds rainwater. The Asian tiger mosquito breeds in surprisingly small containers, including clogged gutters and birdbaths.
Know what is heading back outside
Spring is also when the pests that overwintered inside your walls become active again. The brown marmorated stink bug, which Maryland has dealt with since the insect’s early years in the United States, spent the winter in wall voids and attics. On the first warm days, those stink bugs head for the light, which often means your interior windows.
This is a nuisance, not damage. Stink bugs do not breed indoors or harm the structure. Vacuum up the ones you see and resist the urge to spray inside the wall void, which does little. The real fix is fall sealing, before they get in, which the fall pest article on stink bugs and lanternfly covers.
Check the attic and roofline for wildlife
Spring is den season for Maryland wildlife. Raccoons and squirrels look for sheltered places to raise litters from late winter into spring, and an attic, a chimney, or a soffit cavity makes a good one. By the time you hear activity overhead, there may already be young.
Walk around the house and look up. Check the soffit and fascia for gaps or chewed openings, look at where the roofline meets the walls, and inspect vent covers. A chimney without a cap is an open invitation. Inside, check the attic for droppings, torn or matted insulation, and the smell of an animal. If you find signs of wildlife in spring, do not simply seal the opening, since trapping young inside is both inhumane and a worse problem. That is a job for wildlife removal, which handles the animals first, with attention to Maryland’s bat maternity-season rules, and then seals the entry.
Consider a recurring plan
Spring is the natural decision point for how you want to handle pests through the year. A Maryland home that deals with a different pest each season, termites and ants in spring, mosquitoes and wasps through the long humid summer, stink bugs and rodents in fall, often does better on a recurring quarterly plan than on a string of one-time calls.
A quarterly plan treats the exterior on a schedule that matches the Maryland pest calendar, and it usually includes callbacks between visits if something gets through. Starting one in spring means the house is covered as the pressure ramps up rather than reacting after a problem is established. The residential pest control page explains how recurring service is structured, and the cost guide lays out what quarterly plans run in Maryland.
If a spring walk-through turns up something past the point of prevention, an active ant trail, a termite swarm, signs of a rodent that overwintered, that is the time to bring in a professional. You can get connected with a licensed Maryland exterminator who will inspect the house and quote the work. The services overview explains what each type of treatment covers.
Maryland’s pest year is predictable, and the calendar runs the same way every spring. Getting ahead of it in March and April, with a termite check, a careful seal, attention to moisture, and a tidy yard, pays off all the way through the fall.