According to Dr. Clifford W. Bassett of Allergy and Asthma Care of New York, in addition to carbon dioxide, lactic acid is a strong attractant, which is why people are attacked more when they are outside and sweating.
He recommends insect repellent and taking a nonsedating oral antihistamine for people who react strongly to bites, as it can lessen the itch after a bite, before spending time outdoors.
