Bio-inspired building designs

One of the most beautiful and intriguing buildings I saw at the World Expo 2010 in Shanghai was the British pavilion, called the Seed Cathedral. Unfortunately it was closed the day I visited the expo.
Only now, after watching the TED talk of Thomas Heatherwick on 'Building the Seed Cathedral', I learnt to know that it was a bio-inspired building, capturing hundreds of seeds.

Some other very nice examples of bio-inspired design can be found in his TED talk (do not quit the talk on his rather funny first work he is showing at the beginning of his talk, because the most interesting examples come more at the end).