Migrants rush as they try to get on a train heading to the border with Serbia at the train station of Gevgelija, on the Macedonian-Greek border, on August 9, 2015. Non-EU Serbia's frontier with Hungary, which is in the bloc's passport-free Schengen zone, has become a major crossing point for the huge numbers of migrants entering the EU. (Photo by Dimitar Dilkoff/AFP Photo)

A traditional Russian nesting doll painted with the likeness of President of Donald Trump and his family is displayed for sale at a Moscow store on March 5, 2017 in Moscow, Russia. Relations between the United States and Russia are at their lowest point in years as evidence mounts about the complex relationship between President Donald Trump's administration and the Russian government. (Photo by Spencer Platt/Getty Images)

A woman poses for a photo with the Rafflesia Arnoldii flower at Palupuah Forest, Agam District, West Sumatra, Indonesia on September 16, 2024. Palupuh forest is located at an altitude of 975 meters above sea level, with temperatures reaching 18-20 degrees Celsius. According to The West Sumatera Nature Conservation Agency (BKSDA), in the province of West Sumatra there are 36 points where this endangered flower grows. (Photo by Adi Prima/Anadolu via Getty Images)

Standalone picture dated June 7th, 2022 shows Flt Lt Adam O’Hare rehearsing in the iconic Typhoon plane over Lincolnshire yesterday (Tues) as he trains for this summers airshows with vapour trails over the wing. The phenomenon is caused by low pressure areas created on the aircraft's skin and wings as it moves through moist air. As the pressure drops so does the temperature, and if the temperature reaches the saturation point, water vapor is created. (Photo by Claire Hartley/Bav Media)

A Fulani Pastoralist carries two baby sheep on her donkey cart as her family move on northwards in Barkedji, Senegal on July 21, 2020. Thousands of Pastoralist families will start the movement north in the next weeks. With the first rains comes fresh grass and water for the Fulani herders' livestock, it also marks the point where most of the Pastoralist will move northwards until the dry season. (Photo by John Wessels/AFP Photo)

Hooded torch bearers lead the winter procession through the snow on February 4, 2012 in Huddersfield, England. Imbolc is a pagan festival that marks the half way point between the winter solstice and the spring equinox. Imbolc festivals celebrates the awakening of the land and the growing power of the Sun. (Photo by Bethany Clarke/Getty Images)

After some days with temperatures below freezing point, I was out skating at some lakes at the outskirts of Oslo in Norway. After a while I noticed something on the ice. To my astonishment it was a dead frozen frog.