"A Sociable weaver's giant nest in Namibia, probably the most spectacular structure built by any bird.The Sociable weaver (Philetairus socius) is a species of bird in the weaver family found across South Africa, Namibia and Botswana. This species construct large compound community nests that resemble huts, complete with a sloping thatched-grass roof that sheds rain. These nests are the world’s largest and most populated tree houses, with some weighing up to a ton or more and measuring up to 20 feet wide and 10 feet tall."