Mosquitoes: The bite: You’ve seen it: a soft pale bump that turns red and swollen. Mosquito bites are usually innocuous, but they can carry serious diseases, such as West Nile virus. Treat it: Washing the area with soap and water may diminish your reaction. An ice pack can reduce swelling; soothe itching with calamine lotion or an oral antihistamine. Avoid it: Check your yard for pools of stagnant water (mosquitoes love ’em). If you’re out at dawn or dusk, cover up and/or use a repellent (25 to 40% DEET) on exposed skin.