In Serbia, the traditions surrounding April Fools' Day are quite unique and interesting. Instead of the typical pranks and jokes played on this day in other countries, Serbians have their own set of customs to celebrate April 1st. One common tradition is for people to try and attach a paper fish to someone's back without them noticing. This is similar to the French tradition of "Poisson d'Avril," where paper fish are also used to play pranks. 

Another tradition in Serbia on April Fools' Day is for children to try and sneak up on their friends or family members and stick a small piece of paper on their back. This is done in a playful manner and is meant to bring laughter and joy to those involved. It is a lighthearted way to celebrate the day and create a fun atmosphere among friends and family. 

Additionally, in some parts of Serbia, it is common for people to exchange small gifts or tokens of appreciation on April Fools' Day. This can include things like flowers, chocolates, or other small trinkets. It is a way to show love and appreciation for those close to you, while also adding a touch of humor and playfulness to the day. 

Overall, the traditions surrounding April Fools' Day in Serbia are a mix of fun, laughter, and lighthearted pranks that bring people together in celebration.