If you visit Tokaj at the beginning of June, you might be lucky and witness a very rare and unique phenomenon of "river blooming" - a swarm of mayflies. At sunset, larvae buried in the mud emerge, for a few minutes they transform into winged subimagos, which soon transform into adults that live only a few hours. They fulfill their mission of preserving the family and while the males die immediately, the females fly upstream and release their eggs into the water. Eggs caught on the banks of the river will develop into larvae, which will wait three years for their day when the river will bloom thanks to them. You can see podenkas in Slovakia only on the banks of the Tisa, Bodrog and Latorica rivers.