Yep. By the time you itch they've dropped off.
They're actually mites... in the larval stage.
en.wikipedia.org
I use a product from Sawyer called Picaridin.
Picaridin is a highly effective, synthetic insect repellent designed to be applied directly to the skin or clothing. It is modeled after piperine, a natural compound found in black pepper plants. It provides long-lasting protection against mosquitoes, ticks, biting flies, gnats, and chiggers.
Key Features and Benefits
Picaridin is a popular alternative to DEET due to its user-friendly properties.
Gear-Safe: Unlike DEET, picaridin will not melt or damage plastics, synthetics, fishing lines, or sunglasses.
Comfortable to Wear: It is odorless, non-greasy, and generally less likely to cause skin irritation.
Safety: It is safe for the whole family, including pregnant women and children over 6 months of age.
How It Works
Rather than killing insects, picaridin works by creating a vapor barrier on the skin that blocks insects' receptors. This prevents them from smelling or finding you, making it an excellent tool for preventing vector-borne diseases like Zika, West Nile, and Lyme disease.