These tiny little birds are basically little living disco balls with feathers. During mating season, the male superb Fairy-Wren's feathers change from a dullish brown to a glittery bright blue. Just ...

video: A male first attacking a red-backed fairy-wren mount and then a white-winged fairy-wren mount. view more . Credit: Patricia Leonard, Cornell University. ITHACA, N.Y.

As expected, embryos lowered their heart rates when they heard the fairy wren call—indicating that they were paying attention to this acoustic stimulus—but not when they heard the white noise.

Perth photographer Mark Eatwell spends a lot of time in the Perth hills interacting with splendid fairy-wrens. (ABC Science: Peter de Kruijff)It's not long before the first curious wren emerges ...