Blinking lights in forest and in yard

Blinking lights, 7 or 8, bright green in color and of moderate intensity seen beginning at dark, in forest, at tree line and in my back yard. (This is a forested area.) Slightly cool evening, 63°f,no precipitation, 31% humidity. Lights observed flying at various heights and when moving, parallel to ground.  Please note this is the 5th consecutive year I have seen these lights, they come in Mid April and have been seen multiple times before "leaving" in June. I have made several reports w/ NUFORC over these years.  No noise from lights and I can't see more of them to report a better description.