We'll find out how nature is incredibly inventive and has produced two unique mechanisms of natural construction that have fascinated scientists for centuries; weaving in birds and silk.
Birds nests come in a variety of shapes and sizes, with some made out of some extraordinary materials. Most of the nests that we see are collections of twigs arranged into a loose bowl for birds to safely lay their eggs in.
However, some birds take it a step further.
Weaver birds are unique in their ability to tie knots, working grass into a nest of incredible intricacy. Female weaver birds watch over the tireless males checking their creations for flaws - the ultimate security of her eggs and the fitness of the male and genetic suitability are paramount when making her decision.
Birds nests aren't just a pile of twigs, some are engineering masterpieces.
Silk is the strongest natural material known to man, and here Sir David compares it to steel wire and puts its tensile strength to test.
A perfect mix of proteins give silk its properties and we've found that we can genetically modify goats to produce silk in their milk. Not quite spider-goat, but close enough!
But does silk have applications for us? It turns out that silk could end up saving lives.