If you must apply something at home to kill the ants, spiders or other swarming flying insects, use Windex with ammonia, hair spray, or WD40. If you feel that you must apply some type of chemical, buy Boric acid, but please follow the instructions. It could mean your health. Not all houses can be heat treated, and not all houses need to be fumigated. The inspector that states that a certain process doesn't work really means their company doesn't offer it.
Some companies only offer fumigation or other chemical treatments.
There are only 20 licensees in the State of California. The contractor or home inspector said I have termites . The only inspector or company that can identify termites or other wood destroying infestations or infections must be licensed by Consumer Affairs - Structural Pest Control Board. Next time they tell you that, ask to see their license. All licensees must carry with them a copy of their license or pocket license.