Nest build fresh nests daily out of leaves and other vegetation in which they sleep at night. They sometimes also build nests during the day for resting in. The smaller species of gorilla build their nests in trees, while the larger are confined to the ground. Nests of the western gorilla, the largest species, measure about in diameter. Some species of frog build nests ranging from simple to modest complexity. Many stream-dwelling frogs lay their eggs in a gelatinous mass which they attach to underwater vegetation. The jelly structure prevents the eggs from washing away. Fish engage in nest building activities
Largest prehistoric animals at the shoulders and long. The herbivorous "Cotylorhynchus hancocki" was the largest of the pelycosaurs, with an estimated length and weight of at least and . The biggest carnivorous pelycosaur was "Dimetrodon angelensis", which could reach and . The largest members of the genus Dimetrodon was also the world's first fully terrestrial apex predators. The plant-eating dicynodont "Lisowicia bojani" is the largest-known of all non-mammal synapsids, at and . Among the largest carnivorous synapsids was the therapsid "Anteosaurus", which was long, and weighed . The longest known plesiosauroid was "Styxosaurus" at long. Other elasmosaurs, such as "Albertonectes" and "Thalassomedon", rivaled