When ants show up in a Santa Clara kitchen, it is rarely about the kitchen. Argentine ants nest in the damp soil along irrigation lines, under slab edges and beneath the bark mulch against the foundation, and they come inside when the yard gets too hot and dry in late summer or too wet after the first real rain. That is why spraying the trail on the counter buys you a day or two. An exterminator worth paying is one who goes outside first and finds out where the colony actually lives.
The same logic applies to most of what gets called in around here. Roof rats travel fence lines, palm fronds and the fruit trees in older Santa Clara backyards, then enter attics through gaps at the roofline, dryer vents or the gable where a cable was run and never sealed. Oriental and Turkestan cockroaches live in irrigation boxes, water meters and leaf litter, and push indoors through weep holes and under-door gaps. Yellowjackets build in retaining walls and ground cavities and get aggressive as food sources dry up in the fall. Each of those has a different entry point and a different fix, which is why a flat "we spray the perimeter" answer should make you ask more questions.
Expect an inspection before any product comes out: a walk of the exterior foundation, the eaves and roofline, under sinks and behind appliances, the garage, and the crawlspace or attic if the problem points there. For ants, the technician should be tracing trails to the source and looking at where sprinklers wet the house. For rodents, they should be finding the actual openings, not just placing traps and leaving. Treatment usually mixes non-repellent exterior products at entry points, baits where crawling insects forage, physical exclusion for anything with fur, and sealing where it makes sense. You should get told what was used, where, and what to expect over the next two weeks — ant activity often looks worse before it drops off, because baits are meant to be carried home.
Size and construction of the house, whether there is a crawlspace or an accessible attic, the pest itself, and how far it has spread. A single-story slab home with an ant trail on one wall is a smaller job than a two-story with rats already nesting in insulation. Rodent work costs more than insect work because sealing entry points is labor, and done properly it means ladders, wire mesh and sometimes removing soiled insulation. Recurring service is cheaper per visit than one-off callouts, and for Argentine ants in this climate some form of ongoing exterior treatment is usually what keeps them out rather than a single application.
Ask what they found, not just what they will apply. Ask whether exclusion work is included or quoted separately for rodents, what the follow-up schedule is, and whether the treatment is safe around pets and edible gardens — plenty of Santa Clara yards have both. Ask what you are expected to do: pull food from under the sink, stop leaving pet bowls out overnight, trim branches off the roof, fix the dripping hose bib. Pest work that ignores the conditions feeding the problem comes back.
To discuss a pest issue or arrange an inspection with Tectum Subterranean Barrier, call and describe what you are seeing and where.