18.9 - unusual sight

I know it is hard to make it due to the distance, but those black spots are military helicopters. And not single rotor ones, the kind with 2 rotors on top. This is not something I ever see flying over my area. And they were quiet! You would think 5 if these helicopters flying overhead qould be LOUD but I didn't hear anything until I was outside and even then it was very quiet.