Homemaking (E06)

The animals building trade has craftsmen and cowboys too. Eager to cut corners on building costs, cliff swallows renovate and reuse last year's nests, unneighbourly shags steal materials from next door, and hermit crabs aggressively play the housing market. Expertly engineered, the most desirable dwellings boast air-conditioning, solar heating and defensive moats. But whether building a simple sandy burrow or a massive termite city, the aim of every animal architect is to keep the elements, and unwanted visitors, out. (BBC)