Helicopter and unidentified lights in sky

Helicopter heard while we were inside house. I kept hearing this helicopter over and over and I went outside to look. I saw three different small round lights moving in a uniform direction, one after the other. They appeared to be at a very high altitude compared to the helicopters altitude. These objects moved in a straight path then faded and reappeared once. Finally they disappeared completley. No sound was heard other than the helicopter. Im convinced the helicopter was investigating these objects.