Icaridin works as an insect repellent in two ways - it makes it difficult for flies to land on you and if they do, it discourages them from biting.
So how does it do this? Biting insects detect their 'prey' by sensing the carbon dioxide they breathe out and body heat, and in the case of horseflies, vision is also very important. Fortunately, it doesn't matter that these voracious insects can sense you as their next meal because icaridin literally has you covered, like a Klingon cloaking device.
Although we can't really smell icaridin, insects can. It acts on their olfactory organs (smell) in such a way that it makes it tricky for them to pinpoint you accurately enough to make a safe landing. You will see horseflies, in particular, fly around you before they get fed up and zoom off to find easier prey!
Because of the way it works, it's really important to get good, even spray coverage. Any missed patches won't be fully protected, so they will be an easy target for flies—a chink in the armour that hungry pests will home in on.
Occasionally, a biting fly will land and then fly off again. This is because the icaridin acts as a feeding deterrent, stopping the insect from piercing the skin for a feed.
We've conducted efficacy testing for a period of eight hours with excellent results. Although it works incredibly well, no insect repellent will remain 100% effective for indefinite periods of time. That means it's sensible to take other precautions as well, such as covering up if out for extended periods and unable to reapply.
Getting wet or very hot and sweaty will also reduce the effectiveness of any insect repellent because it makes it more dilute. At the same time, the body is giving off more heat and probably exhaling more carbon dioxide as the respiratory rate increases. All of these are 'I'm here, come and eat me' signals for bloodthirsty insects!
