Strange Mine behavior

I was playing as the Advent last night and noticed that the vasari mines scattered about everywhere would fade in and out of phase space when a scout was in detection range of them. I have observed this behavior and it occurs with the other races as well I believe. The TEC I know for sure. Anyway this stopped when I researched Lingering Presence and I believe it stops for the TEC when you research Timed Explosives. Anybody else notice this? Perhaps they meant for Mine detection to be something that you research to obtain?