Carpet beetle larvae
It has been confirmed by both my local extension office as well as as my exterminator that we have/had carpet beetles; both varied & black. After multiple treatments from chemicals to steam cleaning, I'm certain they are still present. My question at this point is; what's a "normal" amount to still be in our home? If I were to go to anyone else's home and looked closely, would I find any? I realize they procreate rapidly & after 2 years of this battle, I am hoping to have finally gotten a hold of the issue; realizing there will always be bugs in homes. Your professional response will be much appreciated, knowing this will be an approximation & hoping to receive any sort of answer other than "whatever you feel comfortable living among" THANK YOU!
After two years of spraying and steaming your home and belongings have you verified with a specialist in NJ that you still have these carpet beetles? Live specimens would give the best chance for not only an accurate ID but also indicate whether live insects are still in your home.
If you can't find live, verifiable carpet beetles, you're exposing yourself to unnecessary chemical residues and lots of extra work and expense. Since dead insects don't decompose like road-kill, dead beetles can last a long time in a crack or crevice.
If you have removed/eliminated the carpets, clothing, winter wear, etc. that was damaged by the beetle larvae---and you still have live beetles or their larvae in your home, these pests aren't where you're treating. Adult beetles might be annoying, but they are harmless. It's the larvae you want to find; they are the damaging stage. Where they are is where you want to clean up. Get rid of what they are infesting, vacuum and clean that area thoroughly and keep looking in similar places to make sure you got them all.
Carpet beetles---like their kin, the warehouse beetles---are best controlled by systematically searching through materials susceptible to infestation. Find those, eliminate them, clean thoroughly and that should be the end of the problem. Anything made of wool or wool blends, hair/fur/hides (hunting trophies, e.g.), dead animals (mice, rats, bats) in attics, basements, crawl spaces, wall voids---these would be favored host materials and sites that need further checking. That sounds easy, but may not be for carpet beetles, they are so good at hiding. Insecticide would be the last step in pest management rather than the first.
As for how many beetles to tolerate---that can depend on your confidence that the pest problem has been controlled or eliminated. As long as you're finding live beetles, you haven't found what's infested, eliminated it and cleaned that area. When you find that infestation, you'll see why you need to throw out whatever was infested; it will be ruined---big time.