The French artist who spent a week entombed inside a rock began an even more bizarre feat Wednesday -- sitting on a dozen eggs until they hatch.

Abraham Poincheval aims to become a "human hen" by sitting and laying on the eggs inside a glass vitrine at a Paris modern art museum until the chicks emerge.

The performance, called "Egg", could last three to four weeks, with the artist getting only a half-hour break every 24 hours to keep him from cracking.

He is also on a special diet rich in ginger so he can keep the eggs at a minimum of 37 degrees Celsius.

Poincheval, 44, made headlines earlier this month after declaring his seven days inside a rock a mind-altering "trip".

This time, however, he looked distinctly ill at ease as he stepped into the vitrine in the Palais de Tokyo museum in his socks.

He quickly wrapped himself in a heavy traditional Korean cape and sat on a "laying table" specially designed to stop him from accidentally crushing the eggs.

While Poincheval described his time inside the limestone rock as blissful, he acknowledged that sitting on the eggs for such a long time had him worried.

"I have never been so directly exposed to the public before. Usually I am inside something. But every performance is a first," he told AFP.

No 'hen-men' will be eaten

His father Christian acknowledged that it was a test of his mental strength, with the usually amiable Poincheval avoiding eye contact with the crowds gathered around the glass case.

"He is going into himself," his father said, describing the experience of observing his son through the vitrine as "like watching him on TV".

He revealed that when Poincheval was a child he had a pet chicken, and promised that any "hen-men and hen-women" his son brings into the world will be allowed to live out their natural lives on his smallholding in the west of France.

"I have prepared everything to welcome the chicks including a luxury chicken coop. I can assure you that they will never be the centrepiece of a grand feast," said Christian Poincheval, an inventor best known for pills that make flatulence smell of roses and even chocolate.

He saw the performance as a meditation on "the cycles of life. The cycle from egg to chick takes roughly 21 to 26 days, which correspondents almost to a woman's (menstrual) cycle."

His son had said earlier that he was inspired by a tragicomic short story by the French writer Guy de Maupassant.

In "Toine", a bad-tempered farmer's wife gets revenge on her idle bon vivant husband by using his body to keep her chickens' eggs warm when he is paralysed by a mysterious malady.

"Being inside the rock didn't bother me at all," he added.

"Normally there is a moment when your anxiety mounts, but with the rock that didn't happen. I was almost anxious about not being anxious," he said.

After talking to geologists, he put that down to the "extreme calmness" of the limestone.

"I learned it had been laid down gently, layer by layer, over thousands of years, and had never been tormented."

Monkey King

Even though the rock is also egg-shaped, Poincheval said the two performances were not directly linked.

When he emerged from the rock, however, Chinese students told him the story of Sun Wukong, the Monkey King who was born from a stone egg.

Often described as France's most extreme artist, Poincheval is no stranger to bizarre performances.

He once spent a fortnight inside a stuffed bear eating worms and insects; was buried under a rock for eight days; and navigated France's Rhone river inside a giant corked bottle.

He also spent a week last year on top of a 20-metre pole outside a Paris train station.

His big dream, however, is to walk on the clouds.

"I have been working on it for five years, but it is not quite there yet," he said.