This is truly nature's living leaf. I have always loved lying in bed and listening to the late-summer sounds of the katydid. The drone is enough to quickly put me to sleep.
Particularly I used to find the insects most interesting when I was camping. I noticed that the sound fades throughout the night and ends before first light. Have you listened to the drone of a katydid (not to mention their mixture with the common cricket) until you could no longer hear them? It's like starting at a color until you can no longer see it.
Watching a katydid is fascinating to me for their perfect camouflage. What excellence nature provides the dress of this insect! With cold weather, the windows are again closed and the sound has already disappeared.