Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Storm clouds build over a canola field near Cremona, Alberta, Friday, July 29, 2022. (Photo by Jeff McIntosh/The Canadian Press via AP Photo)

A fuzzy caterpillar on a basil plant in west Bengal, India on December 25, 2023. The caterpillar’s defence system is its hair, which has microscopic barbs that break off easily in the skin of would-be predators. (Photo by Soumyabrata Roy/NurPhoto/Rex Features/Shutterstock)

A green jumping spider (Lyssomanes viridis), in a forested area of Cerro de la Muerte, in San Jose, Costa Rica, 20 May 2025. International Day for Biological Diversity is celebrated every 22 May around the world. (Photo by Jeffrey Arguedas/EPA/EFE)

A serviceman kisses the main icon for the Russian Armed Forces' main cathedral, delivered at the Church of Our Lady the Healer in Rostov-On-Don, Russia on May 15, 2018. The Russian Armed Forces' main cathedral is to be built in Patriot Military Park in Kubinka outside Moscow by 2020, the year of the 75th anniversary of the victory of the Soviet Red Army over Nazi Germany in the 1941-45 Great Patriotic War, the Eastern Front of World War II. (Photo by Valery Matytsin/TASS)

Drivers push cars to gas station during “oil crisis”, Roslindale, Boston, Massachusetts, 1973. (Photo by Spencer Grant/Getty Images)

A guard secures gates of a catfish farm visited by a group of foreign reporters in Pyongyang, North Korea April 17, 2017. (Photo by Damir Sagolj/Reuters)

Two Red-eyed Tree frogs (Agalychnis callidryas) mate at “Exotic Fauna” breeding zoo, where exotic animals are reproduced to be marketed as pets in U.S., Canada and Asia, in Ticuantepe, on the outskirts of Managua, Nicaragua on July 17, 2022. (Photo by Maynor Valenzuela/Reuters)