Prevent Insect Bites Many diseases, like malaria and dengue, are spread through insect bites. One of the best protections is to prevent insect bites by: Using insect repellent (bug spray) with 30%-50% DEET. Picaridin, available in 7% and 15% concentrations, needs more frequent application. Wearing long-sleeved shirts, long pants, and a hat outdoors. Remaining indoors in a screened or air-conditioned area during the peak biting period for malaria (dusk and dawn). Sleeping in beds covered by nets treated with permethrin, if not sleeping in an air-conditioned or well-screened room. Spraying rooms with products effective against flying insects, such as those Read More …