The southern masked weaver and lesser masked weaver are among Namibia's most industrious birds, weaving intricate grass nests with a precision and speed that stops even seasoned guides in their tracks. From the male's elaborate courtship display to the tightly woven chamber where chicks will hatch weeks later, the story of the masked weaver is one of instinct, effort and survival. This week's Nature Notes takes a closer look at these small but extraordinary architects of the Namibian bush.