On a hike to Windfall Lake north of Juneau, we take a break in a swampy lowland. Mosquitoes are thick, and we are wearing repellent, and headnets, and full-coverage clothing. Some people claim they are especially targeted by mosquitoes, and it's possible - mosquitoes are attracted by a combination of factors - carbon dioxide in our exhaled breath, warmth, moisture and even darker colors. Someone who is sweating hard and breathing harder is a prime target.
Alaska is home to more than 30 species of mosquito, including the relatively large snow mosquito, which emerges early and can be active when there is still snow on the ground. In all cases it is only the female that bites, requiring a bit of blood nourishment to lay eggs. That tiny amount of blood adds up when millions of mosquitoes are swarming. On the summer tundra of northern Alaska, a caribou can lose up to a pint of blood a day to the hordes.
Mosquitoes can be bad in Alaska, but fortunately they are not dangerous, as they can be in warmer parts of the world where mosquitoes transmit diseases like malaria - caused by a tiny parasite that lives in the mosquito. A mosquito only lives about a month. Alaska's relatively short summers don't provide enough time for the life cycle of the plasmodium parasites and the mosquitos to reach fruition and transmit the disease.