Nikola Tesla (1856-1943) is best known for his pioneering research in electricity and robotics and for his numerous inventions, which include the eponymous Tesla coil.

But the Serbian-born scientist-inventor is also known for his strange obsessions and some truly bizarre behavior. (How many people do you know who have fallen in love with a bird?) Keep reading to learn the details about that and six other strange facts about the man who some consider one of science's great unsung heroes...

1. Tesla had a thing about the number three. A genius, for sure, but Tesla had more than his share of quirks. He was absolutely fixated on the number three, washing his hands three times in a row, and even walking around a building three times before entering it. The obsession may have been a manifestation of obsessive-compulsive disorder (OCD).

2. Tesla detested pearls. Couldn't stand the sight of them. In fact, he hated pearls so much that he refused to speak to women who wore them. What explains his pearly aversion? No one knows for sure--though it, too, might have been evidence of OCD.

3. He was celibate.Married life was not for Tesla, who once said: "I do not think you can name many great inventions that have been made by married men." He reportedly thought that sex would hinder his scientific work.

4. He lived in a hotel room. Tesla lived many years in New York City, and spent his last decade living there in the Hotel New Yorker. He lived in room 3327, a two-room suite on the 33rd floor. It's where his peculiar fondness for pigeons played out (see below).



House where Tesla was born (left) and the church where Tesla's father served in Smilijan. Both structures were burned during Yugoslav wars and rebuilt by the Croatian government.



5. He was unusually fond of pigeons. Lots of folks feed pigeons in the park. Tesla didn't stop there. He used to find ailing pigeons and bring them back to his hotel room. One pigeon, in particular, stole his heart. As he wrote about her, "I loved that pigeon as a man loves a woman, and she loved me. As long as I had her, there was a purpose to my life."



Nikola Tesla in December 1899 sitting in his laboratory in Colorado Springs next to his magnifying transmitter high voltage generator while the machine produced huge bolts of electricity. This image was created by Century Magazine photographer Dickenson V. Alley using "trick photography" via a double exposure. -- Wikipedia

6. He believed in eugenics. Tesla seemed to think that some people just weren't fit to produce offspring. According to Smithsonian.com, he wrote in a 1935 magazine article:

The trend of opinion among eugenists is that we must make marriage more difficult. Certainly no one who is not a desirable parent should be permitted to produce progeny. A century from now it will no more occur to a normal person to mate with a person eugenically unfit than to marry a habitual criminal.

7. He claimed to have invented a death ray. Tesla may have loved animals, but he wasn't all about loving-kindness. In fact, he claimed to have invented a death ray he called "Teleforce," which he said would "send concentrated beams of particles through the free air, of such tremendous energy that they will bring down a fleet of 10,000 enemy airplanes at a distance of 200 miles from a defending nation's border and will cause armies to drop dead in their tracks."