"Deer flies are the bane of summer here in the Northwoods—and around the world. Only Iceland, Greenland, and Hawaii are safe. Just as the black flies become a distant memory and the mosquitoes are relegated to 'mosquito hour' in the evening, the deer flies start interfering with our beautiful, sunny days above 71.6 degrees Fahrenheit," writes Emily Stone, Naturalist/Education Director at the Cable Natural History Museum.