With its bright, blue bill, white cheek patches, and upright tail feathers, the male ruddy duck is one of the more memorable duck species. Like most species, the male has the bright distinctive colors, whereas the female's colors are more subdued. While attracting females or keeping other males away, a male ruddy duck displays behavior known as "bubbling". The male repeatedly slaps its bill against its chest, forcing air out of the feathers and into the water. This produces the "bubbling" effect.
As the nesting period approaches, the ruddy duck generally nests in areas where the vegetation is tall. Occasionally, the ruddy will lay eggs in nests of other ducks such as redheads, grebes, and coots. Once the eggs hatch, the female cares for the brood.