On my QXC in Florida at my first stop, I parked the 172 in the splitting sun and went to find someone to sign my form. The a/c had been sitting idle all week due maintenance and weather. When I came back 30 minutes later, it was crawling with 1000s of ants, instrument panel, seats, controls, air vents... I noticed a congregation around my David Clark's, so took them apart; they had laid literally thousands of eggs in the earpieces. I was able to clean them out and kill the ants in the 172. Of course, when I started the engine, another army emerged from behind the panel...