Record the route between rooms
If ants appear in a kitchen and an adjoining laundry area, note the locations separately. Describe whether a visible line connects them or whether that is only a suspicion. A clear photo of the trail and surrounding surfaces can help explain what you are seeing. Avoid taking apart trim or blocking a route before you have recorded where the activity was most noticeable.
Shared walls can add an access question
In an attached or multi-unit building, tell the person assessing the concern about common walls, shared utility areas, and who controls access. Those connections do not prove the ants came from another unit. They help establish which spaces might need inspection and whose permission is needed. Mention food, water, leaks, and known openings within your own space so the discussion remains grounded in observable conditions.
Ask how the identified ants will be addressed
An appropriate approach depends on identification and the assessment, rather than a generic promise to spray every room. Explain prior product use and any change in the trail afterward. Discuss food surfaces, pets, and children before work is arranged. Ask what progress would look like, which changes you should report, and whether any recommended entry repairs are part of the quoted work.