The itchy insect bites 

Most insect bites are harmless, but they feel unpleasant or may hurt. Mosquito bites usually itch. In some regions, however, insects can also transmit diseases, such as yellow fever and malaria.

The only way to stop mosquitoes from finding you is to confuse their chemical receptors, and mosquito repellents containing DEET do just that. DEET interferes with the mosquitoes' sense of smell, making it more difficult for them
to find you.

DEET-based insect repellents provide protection for longer periods than other repellents.