Mite bites do not usually spread disease, but they can irritate the skin and cause intense itching. Itch mites usually feed on insects, but will bite other animals, including people. The bites usually go unnoticed until itchy, red marks develop that may look like a skin rash. You may notice itching, hives, and swelling around an injury or sore, or a rash of small, red bumps that may or may not bleed. 2  Flea bites are more common on your ankles, in your armpits, around your waist, and in the bends of your knees and elbows.