If you are far enough away (sniping) you often enough won´t see drops coming up, enemys just fall, and then you hop your swallow, drive over and there appears a green item. i don´t like to drive the whole map after every sniper session with my hunter, i want to see right away if something is dropped there aswell as in bulky areas, you only see a few heads of one wave (part two of the strike mission) and take heads. afterwards you will have to check the whole areial for mobs that may hava spawned something behind a trunk or a wall or pillar n stuff