David Rockefeller was known for his passion for collecting insects. The billionaire's collection (his fortune was estimated at $3 billion) comprised about 40,000 various fauna representatives. It consisted of beetles, butterflies, grasshoppers. It is noteworthy that Rockefeller explored this hobby at the age of seven.

Photo: David Rockefeller (right).

Bill Gates, the founder of Microsoft, was not afraid to invest money in the original project Omniprocessor (production of drinking water from human waste). Not so long ago, the businessman visited the plant and was able to independently evaluate the result of the efforts of engineers. After taking a few sips, the billionaire said that he had the purest and tasty water in his glass.

It is worth saying that such projects are very humane. They help people from poor countries cope with a lack of liquid, suitable for drinking.

Recently Yuri Milner publicly stated that he was ready to spend a hundred million dollars on the search for extraterrestrial civilizations. The billionaire also invited Stephen Hawking, one of the most famous physicists of our time, to his team.

This spring, Milner said that he is ready to invest the same amount in the construction of a nanosatellite, which, according to the investor's plan, would be able to fly to the star system of Alpha Centauri for twenty years.

Pavel Durov, the founder of VKontakte social network, surprised his fans with excessive savings. A businessman whose fortune is estimated at $600 million, is renting his own apartment in Berlin on the popular Airbnb website for 70 euros a day.

In 2012, Durov threw paper planes made of money into the crowd from his office window. Every paper plane was made out of a 5,000 ruble bank note.

Georgian billionaire Bidzina Ivanishvili built his own domestic zoo in his private estate. They say that even penguins live in the Ivanishvili's zoo.

An interesting hobby of Mark Zuckerberg is his love to the same clothes. Almost the entire wardrobe of the founder of Facebook social network consists of gray T-shirts and ordinary denim trousers. Answering questions about his style, the billionaire says that he tries to get rid of all the superfluous things in life in this way.

Excessive frugality is a distinctive feature of IKEA brand creator Ingvar Kamprad. An elderly billionaire declares that all his things are bought either in second-hand or flea markets. The businessman admits that he wants to set an example for the younger generation.