K-band excesses detected with interferometry possibly originate from hot (~ 1000 K) dust within an AU from the star. The left sketch shows the typical field of view attainable with a single telescope, e.g., Spitzer (Su et al. 2013) and Hershel (Eiroa et al. 2013), which can resolve the outer cold-debris disk, while the magnified sketch shows the interferometric FOV, which can resolve the inner hot component of the circumstellar disk.