Beavers are of course the big example of a species that essentially builds infrastructure so many more places become safe and productive for them. https://en.w

Beavers are of course the big example of a species that essentially builds infrastructure so many more places become safe and productive for them. https://en.wikipedia.org/wiki/Beaver_dam https://en.wikipedia.org/wiki/Beaver_dam Another spectacular example of an animal building can be seen here: https://www.youtube.com/watch?v=ySXCdcnKBgg https://www.youtube.com/watch?v=ySXCdcnKBgg Note, no that spider did not just dig himself in. He dug a hole first, then took a piece of wood, arranged surface stuff on it and then used a spider web to attach it to a "heavy" (relatively speaking) branch he dragged on top of his hole. The result is a trapdoor. And a heart attack. Other kinds of buildings and infrastructure animals build so they can live further away are of course burrows and holes of all kinds. They protect animals that otherwise would not be able to find shelter from predators during the night (or in cases, during the day), and massively expand the areas where these animals can survive. In many cases those burrows are a conscious choice. If enough easy shelter is available they do not build burrows. https://en.wikipedia.org/wiki/Structures_built_by_animals https://en.wikipedia.org/wiki/Structures_built_by_animals Termite mounds are another example of structures that can be baffling in size (the above ground portion can be as big as a house, the underground portion can be bigger than an aircraft carrier). These structures come fully loaded. They have nurseries, food storage, "farms" for other insects, entrances and exits complete with checkpoints, army barracks, contact points with water streams (quite ingenious ones I might add, you'd think that water would flow in and destroy the whole thing), internal highways, ... Some papers allude that quite a few of them even contain underground trade routes with neighboring termite camps along which they trade commodities. Ants are well known for selectively breeding both the plants needed for their cattle, and their cattle. See: https://en.wikipedia.org/wiki/Ant#Relationships_with_other_organisms https://en.wikipedia.org/wiki/Ant#Relationships_with_other_o... Animals cooperate to achieve common goals. The obvious behavior that gets that is reproduction in solitary species. Hunting in packs. Trekking in packs (from wolves to birds). But I guess you'd want something more "economic" for an example. Ok, let's see. How about Weaver nests ? They're a pretty fucking direct example of building something with -and at least partially for- your neighbor. https://en.wikipedia.org/wiki/Sociable_weaver#Nesting https://en.wikipedia.org/wiki/Sociable_weaver#Nesting