Over 90 of users declared their mosquito bites itch free just minutes after using zap it tested by the world renowned london school of hygiene tropical medicine zap it is an amazingly easy and effective way to treat insect bites simply hold it over the bite and press the trigger button 5 times itching will stop and swelling will reduce within just 5 minutes how does it work a battery free quartz crystal inside the casing generates a tiny pulsating current which inhibits histamine re