Topic
Immune system
2 articles
Biology
Why does a mosquito bite itch?
The bite itself is so gentle you sleep through it. Twenty minutes later there is a hot pink lump that will not leave you alone for two days. Almost none of that damage was done by the mosquito.
Biology
Why do you only catch chickenpox once?
An aunt who had it thirty years ago sits in a room full of spotty children and stays perfectly well. Her skin is no different from theirs. So what is she carrying?