Answer: Bat
Notes: A study revealed the migration strategy of common noctule bats, which travel thousands of kilometers across Europe in spring, using warm storm fronts to conserve energy. The common noctule is an insectivorous bat with a golden to dark brown body, narrow wings, and a powerful flight pattern. It echolocates at low frequencies around 25kHz, audible to some humans, especially children. They inhabit forests, open areas, and urban settings, roosting in hollow trees, buildings, and caves. During winter, they hibernate in caves or urban structures, especially in Eastern Europe. IUCN lists the species as "Least Concern."
