Flickering objects in stationary formationWe live approximately 6 miles south of Elizabethtown, KY, and approximately 16 miles south of Fort Knox. At approximately 2230, on 4 Sep. 14, while walking my dogs, I noticed four bright objects, flickering red/green and hovering in the South/Southwest sky.  At first I thought the objects were aircraft on approach glide path to Louisville Airport (SDF). They were evenly spaced and staggered: 2 aligned and higher in altitude, and 2 aligned at a lower altitude. After observing the objects for about 5 minutes I noticed that they were not moving. The objects in the southern sky appeared as follows:                 *                    *                                                            *                    * I brought my wife and 16 year old son outside to observe, and to help me identify the objects. We noticed a fifth object of similar size and shape flickering red/green to the West at about the same altitude as the other four. We watched the objects for about 20 minutes. The objects did not move from their positions and continued to flicker red and green. Other air traffic moved througout the sky near objects. Objects appeared to react towards aircraft by emitting a beam (very quick to the eye) and/or turning towards aircraft in an aggressive manner.