Pest control in Washington is the alley behind a District rowhouse. Rats use the lane, the gap under the rear door, and the void where the ell meets the older brick. Mice run the party wall into a clean kitchen. Roaches take the warm chase behind the tub. Termites want a damp English basement and any sill that stays in contact with wet soil. The house next door, if it is empty, is part of your condition whether you like it or not.
Describe what you found. Droppings, night noise in a shared wall, wings on a front sill, or mud tubes on the basement wall are different jobs. Do not guess the species if you are unsure. A roof leak that wets wood will keep insects fed after any treatment that ignores it. Pets and children change how the work is done, so mention them. The stoop and the areaway are part of the inspection, not just the kitchen.
Look for gaps at the alley door, open brick around pipes, a hopper window that will not latch, and a stoop that has separated from the front wall. Stored cardboard in the basement gives cover. Ivy and a piled alley give cover outside. One call can cover rodents or insects, but not if the description stays vague. Say whether you see them in the rooms or only hear them in the walls.
If this has come back, say that. You do not need a product name. Mosquitoes in a tiny rear court are a different visit from rats in the structure. Termites are different again. A mid-block house shares risk with both neighbors. An end house has an exposed wall with its own gaps. Say which you are.
Walk the alley if it is safe and note the holes. Pest control in Washington means District alleys, party walls, and basements that stay damp under the stoop. Call the number on this page.