Which rodents will you actually meet in Maryland?
Two species account for nearly everything reported in Maryland: the house mouse and the Norway rat. Knowing which one you have changes where the work happens. House mice are the climbers. They exploit vertical routes, wall cavities, plumbing chases and the gaps around recessed lights, which is why the sound is so often over your head at night. A mouse needs almost nothing to get in, and it stays within a small home range once inside, so droppings cluster tightly along one or two runways. Find those and you have found the roadmap. Norway rats are heavy-bodied burrowers that stay low. They dig along foundations, under concrete stoops, beneath sheds and into old sewer laterals, and they will use a basement floor drain or a rotted sill as a doorway. Because they forage well away from the nest, a rat living under a neighbor's deck can be eating from your compost every night. That range is why rat work has to cover a property line to property line, not just the kitchen where you saw the droppings. The practical difference: mice are a sealing-and-trapping problem in the envelope, while rats are a yard, grade and burrow problem first.
A month-by-month rodent calendar for a temperate state
March through May is the quiet build. Outdoor food returns, breeding restarts, and any animals that wintered in your walls start moving between inside and outside. This is the cheapest month range to do sealing, because populations are low and you are not trapping your way through a crowd. June through August is the outdoor population boom. Summer highs near 87F and humidity around 66 percent keep cover thick and food abundant, so numbers climb outside where you cannot see them. What you notice indoors during these months is usually rats in a crawlspace or garage rather than a full house infestation. September through November is when the phone calls happen. As nights cool toward that median winter low of 26F, everything that spent the summer in a hedgerow or under a shed looks for a heated structure. This is the four-week window in which most homes are colonized. December through February is the loud season. Animals are already in and are moving inside walls for warmth, so scratching gets obvious. You can trap all winter, but sealing frozen exterior gaps is harder, and it often makes sense to trap now and schedule the exclusion work for early spring.
What should the first inspection actually cover?
A real first visit takes an hour or more and produces a map, not a price. Expect the inspector to start outside and walk the entire perimeter, looking at grade level for burrow openings, rub marks and gnawed corners, then work up: utility penetrations, dryer vents, hose bib gaps, garage door corners, crawlspace vents, soffit returns, roofline junctions and the chimney. Inside, they should be in the basement or crawlspace with a light checking the sill plate seam, the pipe chases and the joist bays, and in the attic looking for runways in the insulation, latrine areas and chewed wire. Droppings tell them species and age; fresh ones are dark and soft, old ones are gray and crumble. What you should get at the end is a list of specific openings with photographs, an opinion on which species and how established, and a scope that separates trapping from sealing from cleanup. If a company quotes a number before doing any of that, you have no way to compare it against anyone else's number, because you do not know what is included.
What moves the price of a rodent job?
Nobody can give you an honest figure sight unseen, and the range between two homes on the same street can be wide. Here is what the estimator is actually pricing. Spread comes first. Mice in a single pantry cabinet is a different job from activity in the kitchen, attic and crawlspace, because each area needs its own trapping and its own inspection time. Second is the count and difficulty of entry points: eight openings in accessible vinyl siding is quick, while the same eight in old brick means mortar work and a mason's patience. Cleanup is the line item that surprises people. Removing contaminated attic insulation, disinfecting and re-insulating can exceed the cost of the pest work itself, so ask whether it is in the quote or excluded. Follow-up visits matter too: some quotes include six weeks of trap checks, others include two. Finally, ask what the exclusion warranty covers, how long it runs and what voids it. A cheaper seal with no coverage is not the better deal it looks like.
Rowhouses, party walls and why one unit is never the whole job
Attached housing changes the math, and a lot of Maryland's older stock is attached. When buildings share a party wall, a shared cellar or a common roof deck, mice travel the length of a block inside the structure without ever going outdoors. You can seal your own exterior perfectly and still hear activity, because the animals are entering from next door through a floor joist pocket or an old chase. That means two things for anyone in a rowhouse or a converted multi-unit. First, interior sealing matters as much as exterior sealing: the holes around a shared soil stack, the gap where a joist enters the party wall and the space behind a kitchen cabinet base all need closing with metal, not foam. Second, coordination pays. If neighbors treat at the same time, the population has nowhere to shift; if they do not, you are running a permanent trapping program on animals that live elsewhere. Ask a provider whether they already service adjoining addresses, and whether they will document the shared-wall openings in writing so a landlord or an association has something concrete to act on.
How to compare two rodent quotes without guessing
Put the two proposals side by side and read for scope rather than price. The cheap one is often cheap because it is only trapping. Check five things. Does the quote list the specific entry points found, or does it say sealing in general terms? What materials will close them, since hardware cloth, sheet metal and mortar hold up where expanding foam alone gets chewed through in a season? How many service visits are included, and what happens after those run out? Is droppings cleanup or insulation replacement in the number, or a separate proposal? And what does the exclusion warranty actually promise, for how long, and what voids it? A useful question for either company: if we do this work and I hear activity again in eight weeks, what happens? The answer separates a company that stands behind its sealing from one selling a monthly route. Get everything in writing after the inspection, and be skeptical of any pressure to sign the same day, since a rodent problem that has been building since fall can wait 48 hours for a second opinion.