My house has been treated. Today's treatment chemicals might give five years of protection rather than chlordane's 50 years or more. In general, termites eat slowly. Once you find evidence of an infestation, don't panic. In the month or so it might take to schedule a treatment or carefully research which pest control company to hire, it's unlikely the damage will get much worse.
Termites have straight antennae, and ants have elbowed antennae.
I've had repeated infestations. If you have three or more areas of infestation in the past five years while under contract to a licensed pest control company, it must re-treat your entire home at no charge, according to state regulations. The state does not get involved in damage or repair disputes. I don't have a treatment contract. Once you have a short list to consider, check with the Better Business Bureau for unresolved complaints against a company.