This is the fourth year in a row, when in warm spring evening hundreds of rescued bats return to the wild at Feldman Ecopark during a “solemn release”. A group of volunteers, the Kharkiv bat research group, has been organising this event in order to attract citizens´ attention to vulnerability of nationally protected bats that are living in houses beside people. As bats do not build nests, they roost in tree cavities in summer and return back to the city to hibernate in “cosy” warm crevices of multi-storey buildings. Especially numerous winter aggregations inhabit the buildings of Derzhprom and Karazin Kharkiv National University. In urban environment, bats could often be inadvertently captured by artificial traps, e.g. falling between window panes, or become victims of the animal abuse, but most frequently they would simply awake and accidently leave roosts to find some water or a new shelter. Anton Vlaschenko and Alona Prylutska, zoology graduates from Kharkiv University, have begun to collect these stranded animals and bring them home for rehabilitation. They gave bats food and water, ringed, measured and then placed inside a fridge or between window panes in small cotton bags for further hibernation until the spring. As soon as the number of bats exceeded three hundred, the saviors found themselves in dire straits and began to seek help for establishing a full-scale bat rehabilitation centre. Eventually, it came from the Feldman’s Foundation that provided both indoor space and necessary financial support for the Center in 2013. Every winter, the Center admits and rehabilitates more than 500 bats collected in Kharkiv and handed over from many other Ukrainian cities. As in a real hospital, bat experts alongside with volunteers and young nature lovers feed feeble animals, monitor their hibernation treat bats, and even attend a parturition. More than four thousand bats have been rescued and released by virtue of the Center’s activity. Furthermore, the Center’s staff raises awareness in schools and organises such public events as the International Bat Night Scientific Picnics and various exhibitions. Fieldwork with night mist-nettings in woodlands, annual monitoring of summer and winter roosts along with ultrasonic surveys, virological and morphological studies – all these are inherent details in the research of cryptic flying creatures. Bat experts of the Rehabilitation Center regularly take part in international meetings, presenting results of their studies across Europe. Join us and discover the world of bats!