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
Mammal destruction]], though there are efforts to combat this. [[File:Mammal species pie chart.svg|thumb|upright=1.35|The orders [[Rodent]]ia (blue), [[Chiroptera]] (red) and [[Soricomorpha]] (yellow) together make up over 70% of mammal species. Mammal classification has been through several iterations since [[Carl Linnaeus]] initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums. [[George Gaylord Simpson]]'s "Principles of Classification and a Classification of Mammals" (AMNH "Bulletin" v. 85, 1945) provides [[systematics]] of mammal origins and relationships that were universally taught until the end of the 20th century. Since Simpson's classification, the [[fossil