A nest is a place of refuge to hold an animal's eggs or provide a place to live or raise offspring. They are usually made of some organic material such as twigs, grass, and leaves; or may simply be a depression in the ground, or a hole in a tree, rock or building. Human-made materials, such as string, plastic, cloth, hair or paper, may be used.

Generally each species has a distinctive style of nest. Nests can be found in many different habitats. They are built primarily by birds, but also by mammals (e.g. squirrels), fish, insects (e.g. wasps, termites and honey bees) and reptiles (e.g. snakes and turtles).

The urge to prepare an area for the building of a nest is referred to as the nesting instinct and may occur in both mammals and birds.

Most species of birds build some sort of nest, though some lay their eggs directly onto rock ledges or bare soil without first modifying the area.

Nest types vary from the very simple scrape, which is merely a shallow depression in soil or vegetation, to the elaborately woven pendant or sphere. Some birds will build nests in trees, some (such as vultures, eagles, and many seabirds like Kittiwakes) will build them on rocky ledges, and others nest on the ground or in burrows.

Anthony M. Fadell (born 1969) is a Lebanese American computer science engineer. He was known for being the Senior Vice President of the iPod Division at Apple Inc., having succeeded Jon Rubinstein in 2006. On November 4, 2008, Apple announced that Fadell would be stepping down as Senior Vice President but would remain with the company as an adviser to the former CEO, Steve Jobs. Fadell's wife Danielle Lambert, Vice President of Human Resources at Apple, would leave the company. Fadell is an alumnus of Grosse Pointe South High School in Grosse Pointe Farms, Michigan. He graduated from the University of Michigan with a BS in Computer Engineering in 1991 and was a member of Psi Upsilon Fraternity.

In 2010, he founded Nest, a company which announced its first product, a learning thermostat, in October 2011.

While still at Michigan, he was CEO of Constructive Instruments, which marketed MediaText, multimedia composition software for children. He worked for Apple spinoff General Magic for three years, starting in 1992 as a diagnostics engineer and progressing to a systems architect, where he was responsible for the development of a number of technologies and devices including the Sony Magic Link and Motorola Envoy, both of which were part of the Magic Cap platform. In 1995 he was hired by Philips where he was co-founder, Chief Technology Officer, and Director of Engineering in the Mobile Computing Group, which developed a number of Windows CE-based handheld services, notably the Philips Velo and Nino. Fadell went on to become a Vice President of Philips Strategy and Ventures where he was in charge of developing Philips' digital audio strategy consisting of technology direction for silicon and software, as well as its investment portfolio and potential business models.