Deer Fly Traps

Step 1 Personal protection

I wear one of these whenever I work outside, and they attract and hold whatever deer flies come to bite me. The high fashion added is just a bonus. Deer flies are attracted to any large, dark, warm, moving object (bonus, carbon dioxide exhalations), and the best lure I have available is myself. When I patrol the perimeter of my lot each morning and pick up trash along our nearby highway, I wear the salad bowl ($1). It is drilled in two places and attached by two plastic zip ties to a plastic hard hat that has had its crown cut out. The remains of the hard hat and its webbing hold the bowl onto my head.
When I operate motorized yard equipment, I wear the protective muffs that have a blue Solo cup attached to its frame with wire bag ties through two holes above the cup's rim.
Are they effective? All those dark dots are flies collected in just two weeks' use.
I discard the bowls and cups at the end of the fly season.