Newark, Ohio
The smell is there and nothing is
You know what you are smelling. You have looked in the obvious places, moved furniture, checked the basement, and there is nothing to point at. The search is the job here, and it is the reason this call exists at all.
Nobody public will do this. A municipal crew collects an animal you can show them, which is the arrangement the main Newark page sets out in full. An odour with no body attached to it has nothing to report and nothing to collect.
Or send the details and get a callback.
What actually narrows it down
Smell alone is a poor direction-finder, because air moves through a house along paths that have nothing to do with where the animal is. What narrows it down is everything around the smell.
Flies. The most reliable single indicator there is. A cluster of blowflies at a window, a vent, a light fitting or a ceiling seam usually sits close to the body, because they are trying to get out from where they hatched.
What you heard beforehand. Scratching in a ceiling three weeks ago that stopped, then a smell. That sequence locates the room more often than the smell does.
Where it is strongest at different times. A smell that comes on when the heating runs points at a duct run or a void the warm air is moving through. One that is worst on a still, warm afternoon points somewhere else.
Recent work. A vent capped, a soffit repaired, a chimney topped, a crawl space hatch screwed shut. Animals get closed in, and the timing usually lines up.
Before you spend money on air
Ozone generators, foggers, sealed bags of charcoal and pump sprays all treat the smell, not the animal. While a carcass is still in the building the smell comes back, because the source is still producing it.
Odour treatment has a place, and that place is after the source is out.
The smell outlives the animal
Once the carcass is gone the smell stops getting worse, but it does not stop that day. What soaked into timber, insulation and drywall fades on its own timetable, and two to four weeks is the normal range. Removing the contaminated material around the animal shortens it where that material can be reached.
When the smell is not an animal
Worth ruling out before you pay anybody. A dry trap in a floor drain or an unused bathroom produces a sewer smell people regularly read as something dead. So does a failed sump seal. Run water into every drain in the house and give it a day.
A search can end with no carcass found. That is a real outcome, and you should be told it on the day rather than booked in for another look.
Where the trail usually ends
Most of the time, inside the structure, which makes it a recovery job with everything that implies about walls and access. Sometimes it ends in the yard, under a deck or against a foundation, and turns into an ordinary pickup. Occasionally it is a deer in the treeline that nobody had seen, which is a different job again.
What the search costs
Searching is priced differently from lifting something into a truck, because the time it takes is not knowable in advance. The cost page explains what moves the figure, and you get the number before anyone starts.