Two horses appear to burst into laughter before a sweet embrace. The horses both turn their head to look at the camera and flash their teeth, treating the lucky photographer to a rare shot. Moments later the pair show their affectionate side by coming together and “hugging”. Photographer Nir Amos, 34, said he was “amazed” to capture the horses “laughing” in a field near Skógar, in the south east of Iceland on July 31, 2018. (Photo by Nir Amos/Solent News & Photo Agency)

Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

A rabbit fails to jump over an obstacle during a rabbit track and field competition on the sidelines of a hunting exhibition in Kromeriz, about 60 km east of Prague, on April 1, 2017. Circa 100 rabbits took part in the competition, including disciplines as long jump, high jump and running on a flat track. (Photo by Radek Mica/AFP Photo)

In this February 19, 2017 photo, a couple dances during the “If you don't give me....then you lend me” Carnival street party on Ipanema beach, in Rio de Janeiro, Brazil. The typical view of Carnival in Brazil is anything goes, with no headdress too big, no outfit too small, no song too ribald, but this year some organizers of the world's best known party are drawing the line at lyrics that are sexist, homophobic or racist. (Photo by Silvia Izquierdo/AP Photo)

Pals let their hair down for one last hoorah in Cardiff, capital of Wales on September 12, 2020. Groups of friends crammed into pubs and restaurants to “go out in style” before the “rule of six” is enforced on Monday. (Photo by Huw Evans Picture Agency/The Sun)

An Extinction Rebellion protestor holds up a sign saying “You Can Change Climate Change” in St Martin's Lane in London, United Kingdom on August 23, 2021. (Photo by James Veysey/Rex Features/Shutterstock)

Bullet the bulldog skateboards in a seafront area in the city of Vladivostok, on Russia's Pacific coast on August 9, 2021. The 6-year-old dog learnt how to skateboard two years ago thanks to his owner, Sergei Shukshuyev. (Photo by Yuri Smityuk/TASS)

A leopard attacks a forest guard at Prakash Nagar village near Salugara on the outskirts of Siliguri on July 19, 2011. Six people were mauled by the leopard after the feline strayed into the village area before it was caught by forestry department officials. Forest officials made several attempt to tranquilised the full grown leopard that was wandering through a part of the densely populated city when curious crowds startled the animal, a wildlife official said. (Photo by Diptendu Dutta/AFP Photo)