The world’s largest cobwebs, measuring up to 2.8 square metres (30 ft² 20 in²), are woven by a newly-discovered species of Madagascan spider known as Darwin’s bark spider (Caerostris darwini). It weaves them over flowing rivers by a mechanism as yet undocumented, so that they stretch from one bank to the opposite bank, and some of these are also the world’s longest known cobwebs, spanning 25 m (82 ft 0.25 in).