I've never seen the insects themselves, but i have seen the damage! A very good customer of mine has a rental property, and we clean between rentals. Last time we went to clean, a big square of carpet in the middle of the sitting room was worn down the the backing. Apparently the last tennants had a large coffee table, imported from africa, placed in this exact location, and the owner was convinced that's where the insects had come from. I suggested spraying an insectiside,.... but he wasn't too bothered. He put down a cheap laminate floor instead!!!