Microbat Roosting Box

The Micro Box



Australia is home to a diverse and exciting range of fantastic micro bats. A large proportion now classed as endangered because largely of destructive habitat loss and limited roosting sites. Micro bats are essential for population control of invertebrates with some species eating 500 – 1200 insects including mosquitoes in one night. Some micro bats fly at speeds nearing 50km an hour. All bats use echolocation to find food navigate through the darkness. Wildlife carer’s often need to weigh bats to know what species they have in care! Boxes may also be used to keep micro bats in care, when they first come in and are underweight, injured or during poor weather conditions.




Roosting varies in some cases between species. Caves are home to various species of ghost bats, bent wings and horseshoe bats.


While other species use hollow limbs, crevices under bark or urban situations roof spaces, cavities and even end up indoors. Dormant bats may be seen inside umbrellas, curtains, blankets and old rolls of carpet but especially firewood.




To replace loss of roosting sites, a micro box can be made. Every little advantage will help your local visitors! A Micro Box varies from most other boxes, as there will be a measured entry space that bats prefer when entering a roosting site. Essentially the walls must have large gripping material e.g. Hessian cloth, gutter guard or mesh (non wire) or grooves for climbing. Also necessary is often the use of multiple boxes, bats are largely roost loyal. They will remain within roosting range but have several sites, seasons and food availability. In cooler climates the use of two thickness covers the need for a summer or warmer times of the year and thicker box for cooler months when they are often dormant. Boxes need to be placed on trees higher 4m or more, devoid of branches and foliage for ease of access, prevention of predators. Colonies can vary in size from a single individual to 30 or more. The use of multiple boxes will likely increase your roosting success. The additionally boxes of various entry sizes and box thickness will ensure they remain roosting loyal to you. The use of a large number of boxes will facilitate the loss of your roof space or walls for the micro bats that are evicted from such locations.






Wood – 25mm and 45mm pine/plywood

Stainless Steel Screws



Stainless Steel/brass hinges

Acrylic paint green




Shade cloth

Gutter guard




Size Does Matter Micro Speaking!


Table. 1. Entry hole dimensions which micro bats species preference. However some species are less specific.




12mm – 20mm

15mm – 20mm

Chocolate Wattled Bat  Chalinolobus morio


Gould’s Wattled Bat  Chalinolobus gouldii

Eastern Freetail Bat  Mormopterus sp.


Eastern False Pipistrelle  Falsistrellus tasmaniensis


Gould’s Long-eared Bat  Nyctophilus gouldi


Southern Myotis  Myotis macropus


Lesser Long-eared Bat  Nyctophilus geoffroyi


Eastern Broad-nosed Bat  Scotorepens orion

Large Forest Bat  Vespadelus darlingtoni

Southern Forest Bat  Vespadelus regulus

Little Forest Bat  Vespadelus vulturnus


White-striped Freetail Bat  Tadarida australis




Choose your dimensions for entrance, often use more than one box and cover both sizes.




The box designs requires wood that is rough as possible, as with most wildlife related concerns avoid using particleboard, craftsman and especially treated pine, materials.




illustration. Copyright Wildlife Secrets Pty Ltd.

Micro-bat Roosting Box






Placing The Box


Boxes can be hung in flight paths, suspended by wire, hung around eaves near where entrance to the urban roof space occurred. Using trees where no branches obstruct the successful entry. As with most wildlife boxes higher than 4 metres in the tree, there is some thought that boxes suspended in the flight path of known bats can entice them into a micro box at night. Remember to place where the box is shaded during the heat of the day and from summer weather conditions equally important box must have shelter from wind and rain!






Bats may often take some time before they occupy the box, numbers may vary and even be seasonal. There has been a suggestion that smearing the entrance with bat guano (faeces) may help! Once they are roosting just avoid disturbance around box and tree hosted in.




Hygiene and Safety


There has been much concern about Australian Bat Lyssavirus (ABL) and Hendra Virus in bats more the mega bats especially Flying fox group. There have been deaths (2 in Queensland) from mega bats and some reports that define micro bats can carry ABL. This indicates with prudence that all bites should be medically assessed. Wildlife carer’s that wish to work with bats should become inoculated.




Post exposure vaccination




It is recommended that for any person who has been bitten, scratched, or had a mucous membrane exposure to bat saliva that treatment be commenced as soon as possible. Treatment involves a course of vaccinations that are necessary to protect the person against ABL.




See your GP or hospital immediately following an incident. The Doctor will contact the nearest Population Health Unit to arrange the vaccinations.




If the bat is available and tested and the results are negative for ABL, the course of vaccinations will not be required.




Prompt treatment following a bat scratch or bite is esssential.










Wildlife Secret



Micro bats generate ultrasound that emits from an open mouth or rarely the nose (Horseshoe spp). The return signal allows flying bats to navigate in the dark, find their prey. The reason we cannot hear most micro bats is that the range they transmit is 14,000 – 100, 000 Hz (human hear up to 20,000 Hz). People with very good hearin