Icaridin repels insects and makes them less likely to bite. It works in the same way as DEET by blocking the insect’s sense of smell to the presence of humans. Care Plus Icaridin 20% provides 12 hour protection against mosquitoes and ticks, and 10 hours of protection against black flies. Studies show that Care Plus Icaridin at a 20% concentration repels mosquitoes and ticks at least as well as DEET 30% and provides longer-lasting protection.