Plot twist: Ukraine’s sewer system is basically an aquarium now. A bunch of guppies—yep, those cute little fish from pet stores—have been living and thriving in Kyiv’s polluted wastewater for over 40 years. Scientists say they’re surviving thanks to warm water and strong currents, but now an invasive predator is threatening their weird, dystopian fish society. Who knew evolution had such a wild sense of humor? #Science #Ukraine #Wildlife