As dusk falls, small, silent silhouettes begin circling over parks, gardens, and backyard lawns — creatures most of us associate more with horror movies than with beneficial wildlife. Yet bats are among the most underappreciated allies of urban nature — a single bat can eat several thousand insects in one night, including mosquitoes and crop pests, providing a service to the city that costs us no chemical spray whatsoever.
In this article, we explain why bats deserve far more goodwill than they usually get, what threats they face in the urban environment, how to build and mount a bat box, and what else you can do to support these remarkable mammals in your own garden or balcony. It is a topic that shows protecting biodiversity sometimes starts with overcoming our own, often baseless, fears.
Why Bats Matter for Urban Ecosystems
Bats play a role in ecosystems that is hard to overstate, even though they remain almost invisible to most city residents. As insect predators active at dusk and at night, they occupy an ecological niche filled by no other group — insectivorous birds hunt mainly during the day, so bats are the only significant natural regulator of flying insect populations after dark, including mosquitoes, moths, and beetles considered pests.
A single bat colony living in an attic, a crack in a wall, or a specially built box can eat hundreds of kilograms of insects over the course of a season, with a direct effect on residents’ quality of life and the health of nearby vegetation. Bats are also considered indicator species — their presence or absence in a given environment provides valuable information about the overall state of local biodiversity and air quality.
Myths and Fears That Harm Bats
Many people still see bats through a lens of pop-culture associations — vampires, disease, or getting tangled in hair — almost none of which hold up in reality. Bats living in Poland feed exclusively on insects, do not attack people or pets, and their echolocation system is precise enough that they actively avoid colliding with any obstacle, humans included. These unfounded fears, however, are a real reason why colonies discovered in attics or buildings are sometimes removed, even though bats in Poland are under strict legal protection.
Threats Bats Face in Cities
Bat populations across Europe, including in Poland, have been in decline for decades, and the urban environment, despite the availability of insects as food, creates particular challenges for them. Thermal modernization of buildings, sealing of facades, and the removal of old, unused attics deprive bats of the natural shelters where they have raised young and overwintered for generations.
An additional threat is light pollution — artificial lighting from streets, buildings, and advertising disrupts bats’ daily rhythm, delays the moment they emerge to forage, and can deter some more light-sensitive species from using entire stretches of the urban landscape. On top of this comes the limited availability of insects in heavily urbanized, greenery-poor districts, and the loss of migration corridors — tree-lined avenues and green strips that bats use to travel between foraging grounds and shelters.
Bat Boxes — How They Work and How They Differ from Birdhouses
A bat box differs structurally from a classic bird nesting box, even though both serve a similar function as a substitute shelter. Instead of a round entrance hole at the front, a bat box usually has a narrow slit at the bottom or side, through which the animals crawl inside, mimicking the natural crevices under tree bark or in rock fissures that serve as shelter for bats in the wild.
The inside of such a box is typically divided into narrow chambers by rough partitions that bats can grip and climb, allowing them to hang head-down in their typical resting position. The material a box is made from — usually unplaned wood or a wood-concrete mix — needs to provide adequate thermal insulation, since bats are highly sensitive to temperature fluctuations, especially during hibernation and while raising young.
Where and How to Mount a Bat Box
The effectiveness of a bat box depends heavily on where and how it is mounted, so it is worth keeping a few basic principles in mind before installation.
- Mounting height — the box should be mounted at least 3 to 4 meters above the ground, away from artificial light sources and busy paths, so bats can fly in and out freely without disturbance.
- Sun exposure — locations where the box receives sunlight for most of the day work best, since the warmth helps maintain the right internal temperature, especially in spring and autumn.
- Wind protection — it is worth choosing a spot partially sheltered from the area’s prevailing strong winds, for example against a building wall or tree trunk.
- Patience — bats may only move into a new box after a few seasons, so the absence of tenants in the first year does not mean the box is poorly placed.
It is also worth remembering that bat boxes work best in groups — mounting several boxes in different spots with slightly different exposures increases the chance that at least one will suit the different bat species present in the area.
Other Ways to Support Bats in Your Garden and Neighborhood
A box is just one element of a broader strategy for supporting bats in the environment where we live. Equally important is ensuring they have access to food — reducing pesticide use in the garden and maintaining even a small patch of natural, unmown vegetation encourages the presence of insects that bats feed on.
No less important is reducing light pollution in the immediate vicinity of the garden — turning off unnecessary outdoor lighting after dark, or using fixtures that direct light only downward instead of illuminating the whole surrounding area, genuinely makes it easier for bats to move around and forage freely. Planting native tree and shrub species that flower at night or attract moths further enriches the local food supply for these mammals.
Legal Protection of Bats in Poland
All bat species found in Poland — there are more than a dozen — are covered by strict species protection under national law and the EU Habitats Directive. This means it is prohibited not only to kill or capture bats, but also to destroy their shelters, including inhabited attics or cracks in buildings, even if the site in question is not formally designated as a protected area.
In practice, this means that any planned thermal modernization, roof repair, or facade renovation on a building where bats have been found should be preceded by consultation with a chiropterologist — a bat specialist — who will assess whether and how the work can be carried out without harming the colony, and propose suitable alternative shelters, whether temporary during renovation or permanent.
Why It’s Worth Inviting Bats into the Neighborhood
Inviting bats into your own garden or neighborhood is one of those rare cases where acting for biodiversity brings a direct, noticeable benefit — fewer mosquitoes in the evening, healthier plants thanks to natural pest control, and a contribution to protecting species that have been losing their natural habitats for decades. All it takes is one well-placed box, a bit of patience, and giving up unnecessary outdoor lighting to genuinely support these remarkable, still underappreciated mammals.
We regularly write about similarly simple actions for urban biodiversity in our educational articles, and you can read about how we combine tree planting with protecting wildlife habitats on the One More Tree website.
