Why mosquito eggs float

This hand-coloured scanning electron micrograph was the favourite of the jury in the section "Best Scientific Image". The image shows the surface of a mosquito egg (from Culex pipiens), which generates a water repellent network by connecting microscopically small structures to trap a thin layer of air. The vitally important structures avoid immersion and enable the egg to float and aggregate with neighbouring eggs.

The website of photographer Martin Oeggerli.  Reposted from 2013 because I had my first encounter with mosquitoes this week in the woods behind our house.