Orange oil is the name given to extracts from the peel of citrus.  Mostly this is near pure d-limonene.  It is a general solvent.  You have probably used it in bathroom or hand cleaners.  It kills insects.  I used it as the recommended cleanup solvent for the Blockaid non-toxic termite barrier as it was much less of an OH&S risk than mineral turpentine.

OK, I've crossed out the product name. I don't like going to court. "Fumigation" is when they wrap your house and gas it. In general, the answer is a simple, no. Fumigation means lightweight poison gas that seeps right through your home and into everything, even right into the wood, is generally thought to be bad for the atmosphere and uses a lot of toxin. It does have the benefit of wiping out every last termite that's exposed. It is the best treatment for drywood termites.