Black grouses court at a mating ground in a marsh in the Berezinsky reserve, near the village of Kraitsy, about 140 km (87 miles) east of Minsk, April 22, 2011. REUTERS/Vasily Fedosenko (BELARUS - Tags: ANIMALS ENVIRONMENT) 

Two frogs mate in a pond in Utrecht April 3, 2011. Frog eggs can be seen floating in the water.
REUTERS/Michael Kooren (NETHERLANDS - Tags: ANIMALS) 

A volunteer walks Mathilda, a Jack Russell cross breed as the dog awaits rehousing at Battersea Dogs and Cats Home in London August 2, 2010. The charity, which rehouses stray dogs, said it was forced to put down one-third of the dogs it took in in 2009, despite more than half of them being healthy, as their behaviours posed safety risks. The animal shelter said the issue of stray, aggressive dogs needs to be tackled because a growing number of healthy dogs are being put down as they are too dangerous to rehome. REUTERS/Toby Melville (BRITAIN - Tags: ANIMALS SOCIETY) 

A Staffordshire Bull Terrier cross awaits rehousing at Battersea Dogs and Cats Home in London August 2, 2010. The charity, which rehouses stray dogs, said it was forced to put down one-third of the dogs it took in in 2009, despite more than half of them being healthy, as their behaviours posed safety risks. The animal shelter said the issue of stray, aggressive dogs needs to be tackled because a growing number of healthy dogs are being put down as they are too dangerous to rehome. REUTERS/Toby Melville (BRITAIN - Tags: ANIMALS SOCIETY) 

A volunteer walks Honeybee, a Staffordshire Bull Terrier crossbreed, as the dog awaits rehousing at Battersea Dogs and Cats Home in London August 2, 2010. The charity, which rehouses stray dogs, said it was forced to put down one-third of the dogs it took in in 2009, despite more than half of them being healthy, as their behaviours posed safety risks. The animal shelter said the issue of stray, aggressive dogs needs to be tackled because a growing number of healthy dogs are being put down as they are too dangerous to rehome. REUTERS/Toby Melville (BRITAIN - Tags: ANIMALS SOCIETY) 

Oystercatchers (Haematopus ostralegus) mate on the Pripiat river bank near the village of Turov, some 270 km (167 miles) south of Minsk, May 3, 2010. Several hundred thousand sandpipers, including oystercatchers, migrate through Belarus every spring, according to Belarussian ornithologists. REUTERS/Vasily Fedosenko (BELARUS - Tags: ANIMALS ENVIRONMENT) 

Veterinarians collect semen from a stud bull at a semen collection center in Preska, central Slovenia, April 19, 2010. The center has 50 bulls from which they collect semen from. Each stud bull donates once a week. After checking for quality, the collected semen is stored in liquid nitrogen to be distributed to farmers for cow insemination. In 2009, more then 100 thousand offspring resulted from the center's collected samples, officials said. REUTERS/Srdjan Zivulovic (SLOVENIA - Tags: SOCIETY ANIMALS) 

Storks mate at sunset in Petrovec village, 20 km (12 miles) east of the capital Skopje, March 30, 2010. REUTERS/Ognen Teofilovski (MACEDONIA ENVIROMENT - Tags: ENVIRONMENT ANIMALS) 

Two toads are pictured on their way to a lake in a forest near Darmstadt south of Frankfurt March 23, 2010. REUTERS/Johannes Eisele (GERMANY - Tags: ENVIRONMENT) 

Two toads are on their way to a lake in a forest near Darmstadt south of Frankfurt March 23, 2010. REUTERS/Johannes Eisele (GERMANY - Tags: ENVIRONMENT) 

Two toads are on their way to a lake in a forest near Darmstadt south of Frankfurt March 23, 2010. REUTERS/Johannes Eisele (GERMANY - Tags: ENVIRONMENT) 

A visitor reads about The Chess Player (L), an exhibit at the Body Worlds' "The Cycle of Life" exhibition, at the Science Centre in Singapore October 28, 2009. A controversial exhibition charting life from conception to old age using cadavers has come to Singapore this week -- but without the copulating corpses that caused an uproar in Germany. Body Worlds' "The Cycle of Life" exhibition is one of several around the world that show skinless corpses with muscles and organs revealed, in life-like, often theatrical positions. The specimens are from people who have agreed to donate their bodies for educational purposes. Picture taken October 28, 2009. To match Reuters Life! SINGAPORE/BODYWORLDS REUTERS/Edgar Su (SINGAPORE SOCIETY) 

The world's largest plastination of a body of a full-sized giraffe and a cross section of a giraffe, installations from Body Worlds' "The Cycle of Life", are seen at the Science Centre in Singapore October 28, 2009. A controversial exhibition charting life from conception to old age using cadavers has come to Singapore this week -- but without the copulating corpses that caused an uproar in Germany. Body Worlds' "The Cycle of Life" exhibition is one of several around the world that show skinless corpses with muscles and organs revealed, in life-like, often theatrical positions. Picture taken October 28, 2009. To match Reuters Life! SINGAPORE/BODYWORLDS REUTERS/Rina Ota (SINGAPORE SOCIETY) 

Rearing Horse with Rider, an installation from Body Worlds' "The Cycle of Life", is seen at the Science Centre in Singapore October 28 ,2009. A controversial exhibition charting life from conception to old age using cadavers has come to Singapore this week -- but without the copulating corpses that caused an uproar in Germany. Body Worlds' "The Cycle of Life" exhibition is one of several around the world that show skinless corpses with muscles and organs revealed, in life-like, often theatrical positions. The specimens are from people who have agreed to donate their bodies for educational purposes. Picture taken October 28, 2009. To match Reuters Life! SINGAPORE/BODYWORLDS REUTERS/Rina Ota(SINGAPORE SOCIETY) 

A pair of damselflies copulate as they fly over a weed in Una river near Kostajnica, some 100 km (62 miles) south-east of Croatia's capital Zagreb, August 20, 2009. REUTERS/Nikola Solic (CROATIA ANIMALS ENVIRONMENT) 

Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, 135km (84 miles) southeast of Budapest, June 15, 2009. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during 'Tiszaviragzas' or Tisza blooming season from late spring to early summer every year. REUTERS/Laszlo Balogh (HUNGARY ENVIRONMENT ANIMALS SOCIETY) 

Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, 135km (84 miles) southeast of Budapest, June 15, 2009. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during 'Tiszaviragzas' or Tisza blooming season from late spring to early summer every year. REUTERS/Laszlo Balogh (HUNGARY ENVIRONMENT ANIMALS SOCIETY) 

Long-tailed mayflies (Palingenia longicauda) mate on the surface of the Tisza river near Tiszakurt, 135km (84 miles) southeast of Budapest, June 15, 2009. Millions of these short-lived mayflies engage in a frantic rush to mate and reproduce before they perish in just a few hours during 'Tiszaviragzas' or Tisza blooming season from late spring to early summer every year. REUTERS/Laszlo Balogh (HUNGARY ENVIRONMENT ANIMALS SOCIETY IMAGES OF THE DAY) 

Golden frogs (Phyllobates terribilis) mate in a wooded area, a new section in the Explora park in Medellin June 4, 2009. Picture taken on June 4, 2009. REUTERS/Fredy Amariles (COLOMBIA ANIMALS ENVIRONMENT) 

Voluntary body donor Helm Gaertner (L) and Detlef von Wengler pose for the media next to plastinated human bodies during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

A plastinated human body is pictured during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

A woman looks at plastinated human bodies during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

A plastinated human body is pictured during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

A journalist takes photographs of a plastinated human body during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

Plastinated reindeers and a human body are pictured during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

People look at a plastinated human body during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

A journalist passes in front of plastinated slices of female body during the press preview of the new Koerperwelten ('Body Worlds') exhibition in Berlin May 6, 2009. Anatomist Gunther von Hagens, famous for his Body Worlds shows of plastinated human bodies, has triggered uproar among politicians in the German capital with a new exhibit showing two copulating corpses. REUTERS/Fabrizio Bensch (GERMANY SOCIETY) 

Black grouses court at a mating ground in the Berezinsky reserve, near the village of Kraitsy, about 140 km (87 miles) east of Minsk, April 17, 2009. REUTERS/Vasily Fedosenko (BELARUS ANIMALS ENVIRONMENT) 

Two gold frogs mate at the El Nispero Zoo in El Valle town, Panama April 16, 2009. More than 32 species of amphibians in danger of extinction are being held in captivity to protect them against the contamination of their environment and the Chytrid fungus that has killed a great percentage of amphibia worldwide, the Zoo revealed. REUTERS/Alberto Lowe (PANAMA ANIMALS ENVIRONMENT) 

Storks mate at sunset in Petrovec village, 20 km (12 miles) east of capital Skopje, April 9, 2009. REUTERS/Ognen Teofilovski(MACEDONIA ENVIROMENT ANIMALS ENVIRONMENT IMAGE OF THE DAY TOP PICTURE) 

A pair of Olive Ridley turtles mate along the Bay of Bengal near Rushikulya, about 130 km (84 miles) from the eastern Indian town of Bhubaneswar, January 4, 2009. The turtles have started mating in the sea near the Rushikulya river mouth, enlivening hopes among environmental activists that they may arrive at the coast in the coming months to lay their eggs, local media reported. REUTERS/Jayanta Shaw (INDIA) 

A pair of Olive Ridley turtles mate along the Bay of Bengal near Rushikulya, about 130 km (84 miles) from the eastern Indian town of Bhubaneswar, January 4, 2009. The turtles have started mating in the sea near the Rushikulya river mouth, enlivening hopes among environmental activists that they may arrive at the coast in the coming months to lay their eggs, local media reported. REUTERS/Jayanta Shaw (INDIA) 

Cattle mate as vendors await customers at a cattle market in Nile Delta, 160 km (100 miles) north of Cairo, November 29, 2008. Muslims across the world are preparing to celebrate the annual festival of Eid al-Adha or the Festival of Sacrifice, which marks the end of the Hajj pilgrimage to Mecca by hundreds of millions of Muslims around the world by slaughtering goats, sheep and cattle in commemoration of the Prophet Abraham's readiness to sacrifice his son to show obedience to Allah. REUTERS/Nasser Nuri (EGYPT) 

Performance artists have sex in front of a banner calling for copulation in support of Dmitry Medvedev a few days before his election as president in the Biological Museum in Moscow, February 29, 2008. Carrying bags filled with stolen groceries, the founders of Russia's main radical artist group take out the batteries of their mobile phones before entering their secret home on the outskirts of Moscow. This is to prevent the cops from listening in, said Oleg Vorotnikov, a buoyant 29-year-old art graduate, who co-founded the opposition group Voina, or War. Picture taken February 29, 2008. To match feature RUSSIA-ART/ REUTERS/Thomas Peter (RUSSIA) 

Two pumas in captivity copulate in the zoo in Managua July 10, 2008. Pumas are considered to be an endangered species. REUTERS/Oswaldo Rivas (NICARAGUA) 

Red-sided garter snakes form a mating ball outside their winter den in Narcisse, Manitoba, May 14, 2008. Tens of thousands of snakes exit the dens in the spring to perform their frenzied mating ritual before dispersing to nearby marshes. PICTURE TAKEN MAY 14 REUTERS/Fred Greenslade (CANADA) 

Two camels copulate while on display for potential buyers, two days before Eid al-Adha, in Sahab city on the outskirts of Amman December 16, 2007. Muslims around the world celebrate Eid al-Adha by slaughtering sheep, goats, camels and cows to commemorate Prophet Abraham's willingness to sacrifice his son, Ismail, on God's command. REUTERS/Muhammad Hamed (JORDAN) 

Two camels copulate while their owner waits for potential buyers two days before Eid al-Adha in Sahab city on the outskirts of Amman December 16, 2007. Muslims around the world celebrate Eid al-Adha by slaughtering sheep, goats, camels and cows to commemorate Prophet Abraham's willingness to sacrifice his son, Ismail, on God's command. REUTERS/Muhammad Hamed (JORDAN) 

Lions mate in Masai Mara game reserve October 19, 2007. Picture taken October 19, 2007. REUTERS/Zohra Bensemra (KENYA) 

Bahier, a male liger, is seen in his enclosure at the private zoo "Arche Noah" in the small village of Groemitz on the Baltic Sea coast near Luebeck July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Cilly, a female liger, is seen in her enclosure at the private zoo "Arche Noah" in the small village of Groemitz on the Baltic Sea coast near Luebeck July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Bahier, a male liger, is pictured in his enclosure at the private zoo "Arche Noah" in the village of Groemitz on the Baltic Sea coast July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Cilly, a female liger, is seen in her enclosure at the private zoo "Arche Noah" in the small village of Groemitz on the Baltic Sea coast near Luebeck July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Bahier, a male liger, is pictured in his enclosure at the private zoo "Arche Noah" in the village of Groemitz on the Baltic Sea coast July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Bahier, a male liger, is pictured in his enclosure at the private zoo "Arche Noah" in the village of Groemitz on the Baltic Sea coast July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Bahier, a male liger, is pictured in his enclosure at the private zoo "Arche Noah" in the village of Groemitz on the Baltic Sea coast July 17, 2007. The liger, a result of a breeding of a male lion and a female tiger, was born in the 31-year old private zoo in 1990. REUTERS/Christian Charisius (GERMANY) 

Storks mate on top of a roof in the village of Ruehstaedt about 120 kilometres (74 miles) north west of Berlin April 27, 2007. REUTERS/Fabrizio Bensch (GERMANY) 

A couple of white storks mate in their nest in the Serbian village of Sakule, 40 km (25 miles) from Belgrade, March 24, 2007. REUTERS/Marko Djurica (SERBIA) 

A male Gentoo penguin (R) presents a large pebble to a female as a part of their unique mating courtship at the Edinburgh zoo, Scotland March 13, 2007. The mating season begins in March and lasts for 4-6 weeks when males who suffer from 'pebble envy' steal the best looking pebbles from other nests to take to their own. REUTERS/David Moir (BRITAIN) 

Bonobo apes, primates unique to Congo and humankind's closest relative, copulate in a pond at a sanctuary just outside the capital Kinshasa, October 31, 2006. Scientifically named Pan paniscus, but more commonly known as pygmy chimpanzees, bonobos share 98.4% of their genetic make-up with humans and are at risk of extinction due to more than a decade of conflict in Central Africa. REUTERS/Goran Tomasevic (DEMOCRATIC REPUBLIC OF CONGO) 

-PHOTO TAKEN 05APR06- A technician prepares irradiated fruit-flies for export at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

-PHOTO TAKEN 05APR06- A technician irradiates fruitflies at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

-PHOTO TAKEN 05APR06- Workers tend to fruit-fly larva at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

-PHOTO TAKEN 05APR06- A worker collects fruit-fly larva at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

-PHOTO TAKEN 05APR06- A worker checks fruit-fly egg production at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

-PHOTO TAKEN 05APR06- Fruitflies lay eggs at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre [nuclear war] against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable [industry in California and Florida,] are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the [United States.] As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. 

Irradiated fruitflies are prepared for export at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre nuclear war against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable industry in California and Florida, are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the United States. As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. TO GO WITH FEATURE GUATEMALA FLIES. REUTERS/Daniel LeClair 

Fruitfly samples are quarentined for quality control before being exported from the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre nuclear war against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable industry in California and Florida, are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the United States. As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. TO GO WITH FEATURE GUATEMALA FLIES. REUTERS/Daniel LeClair 

Workers prepare fruitflies for irradiation at the MOSCAMED facility in El Cerinal, Guatemala April 5, 2006. Every week, Guatemalan scientists blast 2.7 billion fruit flies with radiation to make them sterile in a bizarre nuclear war against one of the world's most destructive farm pests. The flies, a threat to the fruit and vegetable industry in California and Florida, are then dropped from planes to copulate with fertile females in Guatemala, Mexico and the United States. As a pest control method, it is easier than killing flies, which once they infect a crop can reduce yields by over 50 percent. Picture taken April 5, 2006. TO GO WITH FEATURE GUATEMALA FLIES. REUTERS/Daniel LeClair