Bat droppings found - what to do?

Bat droppings found - what to do?

the essentials in brief

  • Bat droppings are 3-15 mm in size, elongated and dark brown to black in color.
  • Hobby gardeners who are close to nature collect bat guano (€ 10.44 from Amazon *) and use the pellets as an organic, nutrient-rich plant fertilizer.
  • Anyone who finds bat droppings minimizes the dangers for the endangered animals: attach mosquito nets, cover rain barrels, avoid chemical wood protection, pigeon sticks and toxic pesticides.

What does bat droppings look like?

bat droppings

Bats invariably feed on insects. Mosquitoes, beetles, spiders and moths are on the menu. This food shapes the appearance of bat droppings. The following table gives an overview of the appearance and properties of bat solution:

also read

  • The right location for a bat nest box
  • Building instructions for a bat box
  • Animals in hibernation - what is it and who makes it?
Bat droppingsproperty
size3-10 mm (rarely up to 15 mm)
colourdark brown to black
shapeelongated, pellet-shaped
consistencydry, shiny
Specialtyvisible insect remains
infection riskNo

Bat droppings are not dangerous. The excrement does not contain any poisonous pathogens that are harmful to humans or pets. Feces and urine also do not contain the dreaded rabies virus. Bat rabies is only transmitted through saliva in skin wounds. As long as you don't touch bats, there is no danger. Even rabid bats never attack a person of their own accord. Found, weakened, flightless animals should be picked up with thick leather gloves.

Common locations

Bat droppings always accumulate near roosts, hiding places and nurseries. Experts refer to the grouping of several females as a nursery to raise their offspring together. The following sites are characteristic of bat solution:

  • Under an attic
  • In the attic
  • At the chimney
  • Under roof tiles
  • Behind shutters
  • In the roller shutter box
  • In cracks in the wall
  • In tree hollows and cracks in bark

The following picture illustrates typical locations of bat droppings on the house:

Bat droppings found on the house

Bat droppings on and in the house - what to do?

Finds of bat droppings on and in the house are cause for joy. Indeed, one of the hardest-working insect-eaters has found its way to you. A single pipistrelle bat eats up to 2000 mosquitoes per night and pays rent for the accommodation in this way. The nightly feast leaves plenty of bat droppings, which you should not throw away unused. Furthermore, found fecal pellets are a good reason for important precautions to protect the strongly threatened beneficial insects. The following table summarizes what to do with bat droppings on the house:

What to do?Options
Useas plant fertilizer
Minimize dangers+ Protective nets on windows
+ cover open vessels
+ no chemical wood protection
+ no pigeon defense skewers
+ no glue traps
+ no pesticides
Set up quarters+ Build quarters
+ Hang up nesting boxes
Ask expertsCall the bat hotline

The correct way to use the options mentioned is explained in more detail in the following sections with practical tips for a bat-friendly environment in and around the house.

Use bat droppings - nutrient-rich plant fertilizer

bat droppings

Bats are natural treasures in many ways. This even applies to their droppings. The excrement is a special variant of guano, which is exceptionally not produced by birds and is called bat guano. With up to 8.5 percent nitrogen and other valuable components, bat solution proves to be a superlative natural fertilizer for the hobby garden. If the winged suppliers have rented themselves from you, you will receive the organic nutrient supply for your plants for free. How to use bat droppings as plant fertilizer:

  1. Put on gloves, arm with a bucket and shovel
  2. Collect bat droppings
  3. Sprinkle thinly by hand in the bed
  4. Work in on the surface with the rake and pour in

Alternatively, you can make an organic liquid fertilizer from bat guano. Stir 3 tablespoons of dung crumbs into 1 liter of rainwater and let the mixture sit for a few hours in a shady, cool location. With a pH of 7.5, solid or liquid bat fertilizer is suitable for most vegetables, shrubs, woody plants and flowers.


Bats are protected

All 25 bat species in Germany are seriously threatened with extinction. Horseshoe bat, noctule bat, and conspecifics are therefore subject to the Federal Nature Conservation Act or are even listed on the Red List of Threatened Species. Numerous European and international laws are dedicated to the protection of bats so that the extraordinary mammals do not become extinct. In principle, it is illegal to hunt, kill, or disturb bats or to destroy their summer and winter quarters.

Minimizing the risk to bats - tips & tricks

bat droppings

Did small crumbs of excrement reveal that you are hosting bats? Then animals worthy of protection have come to you. Various death traps lurk around the house and in the garden for the shy night owls with a great appetite for insects. Here's what you can do to minimize the dangers:

Fly screens on windows and doors

Tilted windows and open doors become an entry lane for stray bats all year round. When hunting prey or looking for summer or winter quarters, the animals stray from the right path. Once stranded in the house and apartment, the frightened bats cannot find their way out and pay for the mistake with their lives.

This tragedy can be avoided with simple fly screens. Install insect protection nets on windows and doors, while keeping annoying flies, mosquitoes and other pests at bay. Before installation, please check that there are no bats hiding in the roller shutter boxes, window and door crevices that would be trapped without help. It is important to note that you leave the protective grille in place all year round.

Cover for rain barrel & Co.

Worthwhile measures, such as collecting rainwater or producing nettle manure yourself, harbor a deadly danger for innocent bats. The flying gnomes often perish in open vessels of all kinds. For this reason, please cover the rain barrel, slurry tank, bucket and watering can with a close-meshed wire mesh or lid.

Paint biological wood protection

By using environmentally friendly wood preservatives you are doing good work for your family, for nature and especially for endangered bats. You can recognize recommended wood glazes, impregnations and colors when shopping by the “Blue Angel” environmental label. The Bat Conservation Association Baden-Württemberg has published a list of wood preservatives that are explicitly bat-friendly at

Pigeon defense without skewers

bat droppings

When it comes to keeping pigeons away, nature lovers consistently refrain from using stainless steel or plastic skewers. Not only pigeons and songbirds can be impaled by the spikes. In the dark, bats often recognize much too late the deadly danger lurking on the roof, balcony and window sill. If pigeon droppings make life difficult for you, flexible pigeon repellent spirals and effective pigeon droppings are the better solution because there are no fatalities to complain about.

Control insects without sticky traps

Sticky traps play an important role in insect control and monitoring. For unsuspecting bats, sticky traps mean a slow and agonizing death. If you find bat droppings on your property or building, please remove all sticky traps. The hungry bats will be eager to hunt annoying insects anyway.

Pesticides taboo indoors and outdoors

Rigorously avoiding pesticides turns your home and garden into a paradise for birds, bats and hedgehogs. Chemical poisons kill the winged and prickly beneficial insects through the back door. On the one hand, the insectivore's food source is destroyed. On the other hand, birds, bats and hedgehogs hit poisoned, living insects hard on the stomach when they are eaten.

Setting up bat roosts - nest box tips

There is a great housing shortage among bats. If you find bat droppings in a place that is completely unsuitable as a daytime hiding place in summer or winter, you can set up safe alternative quarters for the animals in need. Tried and tested constructions are available for purchase in specialist shops, which are also suitable as nesting boxes (€ 8.76 at Amazon *) or nursery. We have summarized important information for beginners below:

Flat boxes for crevice-dwelling bats

bat droppings

This type of box is most commonly used and can also be built by yourself. With a shallow depth, flat boxes are ideal for all bats that prefer narrow gaps with stomach and back contact. The slight inclination of the front wall is advantageous on the Hasselfeldt and EMBA models. The well-known Schwegler model has a door flap with different thicknesses, the depth decreasing from bottom to top or from right to left. In this way, bats of different sizes find a home here.

Bat droppings cannot collect in flat boxes if they open at the bottom. This is also a good solution for hobby gardeners, because the rich bat guano is simply collected from the ground.

Round boxes as day and mating quarters

The classic tit nest box was the inspiration for this box version for bats. Instead of a pointed roof, there is a dome roof and a removable front wall for cleaning work in spring and autumn. Inside a round box there is a corrugated wall made of wood concrete for large bats, which like to rest while hanging. Some box models have additional, horizontal inner walls so that there is also space for small bat species.

A slip tunnel on the front prevents the animals from getting dirty with faeces when crawling in. Luxury models have a sloped floor and an open crevice so bat droppings can fall out.

Large caves as winter quarters or nursery

Large-capacity caves more than double the volume and size of normal daily round boxes. Insulating double walls guarantee reliable frost protection in winter. Grooved inserts create sloping surfaces on several levels, ideal for a cozy nursery. However, large caves for bats add a considerable weight of 15 to 30 kilograms.

Built-in caves for the house facade

Bat-friendly builders include bat caves in their plans, which can be integrated decoratively and discreetly into house walls. Since the housing shortage among bats has spread, the market demand for permanent facade installation caves has increased. The range of models is correspondingly broad. The variants range from stackable building blocks based on the modular principle to walled-in gable tubes. Generous accommodation providers choose solutions with an opening in the back wall to give shy guests access to the attic accommodation.


A finger test reveals the furry culprit: Bat droppings are shiny, crumbly and dry, and disintegrate when you rub them between your fingers. Mouse feces, on the other hand, harden within a short time and do not disintegrate. Please wear gloves when putting the test to the test.

Ask bat experts - NABU bat hotline can help

The Naturschutzbund Deutschland (NABU) vehemently dispels the myths, legends and prejudices that circulate about bats. In the meantime, the intensive educational work has generated great interest in the true nature of flying mammals. This raises a lot of questions, and not just about bat droppings. For this reason, NABU has set up a nationwide expert hotline:

Bat phone: 030-284984-5000

The office hours are coordinated with the bat season. From June to August, the experts are at your side with good advice from 10 a.m. to 4 p.m. and from 7 p.m. to 8.30 p.m. You can reach the experts personally on Saturdays, Sundays and public holidays from 11 a.m. to 1 p.m. and from 5 p.m. to 7 p.m. Outside the high season, the office hours are slightly shorter.

frequently asked Questions

Can you build a bat nest box yourself?


With a little manual skill you can build a bat box yourself. You can find recommended construction management at or in the download area of ​​ Use splinter-free, rough sawn wood as building material. If anything, the nest box should only be impregnated with linseed oil on the outside. Furthermore, the bat refuge should be breathable so that no mold forms, and it should not have tar paper as a roof that could melt when exposed to sunlight.

Bat droppings regularly accumulate on my windowsill. What to do?

It is actually a reason to be pleased that an endangered bat has found safe shelter with you. If the brown crumbs of excrement on the windowsill bother you, why not make a virtue out of necessity. Set up a decoratively planted flower box (€ 13.18 on Amazon *). From now on, fallen bat droppings can no longer be seen and your plants benefit from the free fertilizer.

Do I have to report the discovery of bat droppings because it indicates the presence of bats?

No, bats or sites with bat droppings do not have to be reported. Nonetheless, the bat experts at NABU are happy to receive information about where to stay, which gives reason to hope that the flies will be saved. There is also an award for people who tolerate bats around the house or in the garden.


Hobby gardeners with a big heart for small bats create a natural garden with nesting boxes. If night-flowering plants are on the design plan, the food supply for bats increases when searching for prey at night because insects cavort here in droves. Where nodding celibate (Silene nutans), red carnation (Silene dioica) and chicory (Cichorium intybus) thrive side by side, the table is set for growling bat stomachs.