Read in NRC Next this morning (the got it from Science): recent research has shown that dengue mosquitos, the ones responsible for yellow fever, adjust their mating buzz until they sound in harmony.
Normally, male mosquitos buzz at a frequency of aroud 400 Hz, and female ones at 600 Hz. But when two potential lovers meet, they adjust their buzz until they create a harmonic of about 1200 Hz. When the male has reached the correct overtone, they start mating.
Ehm...well, considering that I'm on an overtone singing course right now...should my partner start worrying? :-)