In some cases EXTERRA Termite Baiting is your best option
We recommend the EXTERRA Termite Baiting system be used in and around a building as part of an integrated termite control and monitoring program, where (1) a complete chemical treated soil barrier using Termidor or Premise is not practicable or desired and (2) where several thousand termites are most likely to consume the EXTERRA Termite Bait, within 30 days, that is, live termite activity site is found.
Source: Termite.Com