Saturday midday I was walking along the "Wandle Way" in Merton (SW London)
when there was a light shower with weak sunshine. Almost at once every gap
in tree cover along the river bank was filled by clouds of tiny, pale,
flying things.

They did not seem to be hostile, but one had to be very careful not to
swallow some or get them in the eyes. I have never seen so many before. It
made us realise that tales of fishermen being smothered by swarms on some
African lakes were not far fetched!

-- 
Rodney Blackall (retired meteorologist)(BSc, FRMetS, MRI)
Buckingham, ENGLAND
Using Acorn SA-RPC, OS 4.02 with ANT INS and Pluto 3.03j