The nocturnal creatures were saved and treated over the winter months in Ukraine
More than 500 rescued bats have been released from a special rehabilitation center in Kharkiv. Dozens of people turned out to see the nocturnal creatures fly off into the wild - but not before getting a rare closer look at the mammal. The bats only recently woke up from hibernation after being saved prior to Ukraine's bitter winter.
Valeriya Hazarenko, naturalist: "Every time, we weight the bats before and after we feed them. We also give them water to drink and food to prevent them from losing weight, because, if the bat does lose weight, it could die."
These bats were originally handed in by members of the public. They were found in hidden away places - for example, elevator shafts, ventilation systems, rooftops and window frames. But looking after the bats is not so easy. Sometimes, they have to be treated for injuries - including broken jaws.
Elena Podenko, volunteer at the Bat Rehabilitation Centre: "This bat has been on a rather long course of rehabilitation - for two months, it couldn't eat by herself whatsoever. We fed her with maggots using some tweezers and now, the bat is completely healthy."
Meanwhile, the director of Rehabilition Centre says the bats are essential to maintain balance in the ecosystem - and despite carrying virus, they are not as harmful as people often think.
Anton Vlashchenko, Bat Rehabilitation Centre Director: "They can transmit viruses as well as rabies but not suffer from them themselves. But the virus they transmit is not the same as the one transmitted by foxes, cats and dogs. It's not that dangerous for humans and animals."
Although the bats have their freedom, volunteers are still keeping watch on them - through special microchips attached to their wings - so their migration can continue to tracked from the rehabilitation HQ in Kharkiv.