Tony Fadell

You have to look at why people come and work at Nest. Part of it is that a lot of people here already know each other, but we're also on a mission with a purpose. People are personally motivated by energy or safety.

While I was designing my home, I was living in different houses all around the world, and I saw thermostats that were just as bad as the ones in the U.S., or houses that needed them but didn't have them. I realised that this was a worldwide problem. I thought, 'Let's fix it.'

It is only when you watch the dense mass of thousands of ants, crowded together around the Hill, blackening the ground, that you begin to see the whole beast, and now you observe it thinking, planning, calculating. It is an intelligence, a kind of live computer, with crawling bits for its wits.