u/Due_Pin2723

In the end of the episode, when Mulder and Scully were escaping in a Jeep with the US Forest Service employees and the "ecoterrorist" Doug, the Jeep hit the caltrop and stopped. Doug went outside the Jeep and was swamped by the bugs, cocooned, and killed when the headlights were still on.

What I don't understand is, since the headlights were still on, shouldn't that be enough to stop the bugs? Wasn't the safest position for the group be within the beams of the headlights when the car stopped and they wait until the morning? I just don't understand why the light worked at the house but didn't work when they were outside. Any thought?