Might have been the bee swarm in May. (June must be fly month.)
'Thousands of bees' swarm White House
5/16/10
Found it.
June 18, 2009
What Has 132 Rooms and Flies?
By MARK LEIBOVICH
WASHINGTON The White House is bugged!
No, not like that. But actual flies are swarming the place, confounding housekeepers, irritating aides, even trying to feast on the president. During an East Room interview with John Harwood for CNBC and The New York Times on Tuesday, a giant fly orbited Mr. Obamas head.
http://www.nytimes.com/2009/06/18/us/politics/18fly.html?_r=1&pagewanted=print