Which of the four animals do you actually have?
Location narrows it faster than anything else, because these species barely overlap. If the noise is above a ceiling and sounds heavy with long pauses, you are listening to a raccoon. Raccoons are strong enough to pull a vent screen out with their hands, so the entry is often torn rather than chewed, and droppings collect in one repeated latrine spot instead of scattering. If the noise is under the floor or in a crawlspace, is slower and clumsier, and there is only one animal, it is more likely an opossum. They do not usually nest in groups and they leave less structural damage behind, though the mess is the same. If there is a smell before there is a sound, and it sits at ground level near a deck or shed, it is a skunk. They den at or below grade and rarely climb, so overhead noise rules them out. And if there is no noise in the house at all but holes are appearing near hardscape, you have California ground squirrels. That one is not a building problem, it is a soil problem, and it needs a completely different plan.
The rules California puts around the job
Two state requirements shape what a legitimate San Diego operator can offer, and both are worth knowing before you make calls. The first is relocation. A raccoon may not be relocated without written permission from the Department, and furbearer seasons are set at the state level. That removes the option most homeowners imagine when they picture wildlife removal, which is a cage in a truck bed and a release somewhere green. What replaces it is exclusion, where the animal leaves on its own through a one-way device and the building is sealed behind it. The second is licensing. Trapping for hire in California requires a state trapping license, and that applies to commercial wildlife trapping generally rather than to a single species. It is a fair question to ask on the phone, and the answer should be immediate. Taken together, these rules push the value of the job into the sealing and the inspection rather than the catching. When you compare companies, the meaningful differences are how carefully they searched and what metal they are putting over the holes.
Ground squirrels and the hardscape you are standing on
The most expensive wildlife damage in San Diego is usually invisible until something tilts. California ground squirrels dig extensive burrow systems, and they favor the edges where soil meets built structure: patio slabs, walkways, driveway aprons, pool decks and the footings of retaining walls. What you see first is a cluster of entrances a couple of inches across, often partly hidden by ground cover. What you see second, months later, is a paver that has dropped a quarter inch, a crack tracking across a walkway, or a section of wall that has begun to lean. At that point the wildlife work is the small half of the bill. Managing a colony is not a single visit. It combines removing the cover that makes the area attractive, which means clearing brush, woodpiles and dense ground cover back from slab edges, with barriers of buried galvanized hardware cloth along the edges being undermined, and with direct treatment of the burrow system by a licensed operator. The part homeowners control is the habitat. Squirrel colonies expand into cover and stall in open, exposed ground, so a cleared two-foot band along a wall does more than it looks like it should.
What a first visit should include in San Diego
Expect most of the visit to happen outdoors. A technician who goes straight into the attic and back out has skipped the search that finds openings two and three. The ground lap comes first and matters more here than in colder cities: the entire perimeter looking for burrow entrances, dig sign at slab edges, disturbed ground cover along walls, and chewed irrigation. Then the roof pass, covering eaves, soffit returns, roof-to-wall junctions, chimney, plumbing stacks and dryer vents. Then interior entry into both the attic and the crawlspace with a light. What you should receive is a written scope with four parts. How the animal exits. What material closes each numbered opening. Whether any ground barrier work is included. And what happens to soiled insulation, priced separately or not. One extra question is worth asking before the technician leaves: are there young. Because litters here arrive in spring and the weather never forces a schedule, this is easy to get wrong, and a one-way door installed over a nest strands the young inside. A company that checks before installing has saved you a second, worse call.
Why prevention here is mostly plumbing and pruning
In a climate averaging about 10 inches of rain a year, animals are not looking for shelter from weather. They are looking for water and cover, and both of those are things a homeowner controls directly. Start with water. A dripping hose bib, a cracked drip emitter, a leaking irrigation valve, a pool deck that stays wet, and a pet bowl left out overnight are the five reliable water sources on most properties. Closing those does more to move animals along than any repellent product, because a den close to water beats a den far from it every time. Then cover. Dense ground cover against a slab edge, a woodpile along a fence, ivy climbing a wall, and unharvested citrus on the ground all say the same thing to an animal: safe here, food here, stay. Clearing a band of open ground around the foundation and along retaining walls removes the sense of security that keeps a colony expanding. Finally, access. Cap the chimney, screen the vents with metal, and latch the crawlspace panel. Those three take one afternoon and close the routes that produce most of the calls.
Renters, owners and shared buildings
The division of responsibility is simpler than most people expect once it is written down. Closing a hole in the building is the owner's job, because it is a repair to the structure. Screening a foundation vent, capping a chimney, replacing damaged fascia and latching a crawlspace panel all sit on that side of the line. Attractant control sits with whoever lives there. Garbage in a latching container, pet food and bowls indoors overnight, fallen fruit picked up, and no open access panel are daily habits rather than repairs, and they matter more in a place with no dormant season than they would somewhere with a hard winter. Tenants get action faster with a record than with a phone call. Log the hour of activity for three consecutive nights, photograph droppings and any visible opening, and send a dated written request. Where there is a health element, such as a bat found indoors or a possible bite, say so explicitly in that message and keep a copy. For owners of multi-unit buildings, treat the crawlspace as one shared space rather than several. An animal under unit one is under all of them within a week.