As temperatures rise in spring, bats become more active. In Japan, the Japanese house bat, which can settle in private homes, is found nationwide. These bats enter buildings through small gaps and cracks, causing various types of damage. In reality, however, it is often difficult to notice that bats have taken up residence in a home. Many people feel uneasy because they sense an animal presence but cannot tell whether it is a bat or a mouse. BEST Inc., a company that addresses household concerns and is headquartered in Yokohama, Kanagawa Prefecture, has spent more than 20 years solving everyday problems. Its information site, Gaichu Gaiju Concierge, publishes accurate and useful information about pests and nuisance wildlife. The company conducted an original survey of people who had experienced bats living in their homes, collecting 167 valid responses. The survey found that many respondents realized bats had settled in their homes after seeing them flying. This release introduces what led people to notice bat infestations, the specific damage they experienced, removal methods, and costs. It is intended as a useful reference for people worried about bat-related damage. Survey overview: respondents were people across Japan who had experienced bats living in their homes; the survey period was February 25 to March 5, 2025; the survey was conducted in-house; responses were collected voluntarily online; valid responses totaled 167. About 80% noticed because they saw actual bats. The most common triggers for realizing bats had settled in a home were “seeing them outdoors, such as in a garden or on a balcony” at 49.7% and “finding droppings” at 44.9%. This was followed by “seeing them inside a room or hallway” at 31.1%. Many people have seen bats around their homes, but they may not simply be flying by; they may already be living nearby. It is not unusual for bats to rest on balconies or exterior walls near entrances and then slip inside. Many people also notice bats throu