Minnesota Bat Roost Watch
Minnesota’s bats need your help!
To learn how bat populations are changing in response to white-nose syndrome and other pressures, we are seeking volunteers across Minnesota to help us learn where bats roost and raise their young (called “pups”).
We wouldn’t be able to collect this data without help! Partnering with volunteers allows us to collect much more information than we ever could alone.
This project is led by the MN DNR Nongame Wildlife Community Science Program and Minnesota Biological Survey to document:
Where bats are roosting and rearing pups throughout Minnesota
How bat populations are changing over time
How bat populations are responding to white-nose syndrome
What will Bat Roost Watch volunteers do?
Volunteers can participate in this project in two ways:
1. Report Bat Roosts
We need to know where active bat roosts are located throughout the state. Common roost locations include bat boxes, attics, garages and barns.
What you will do: If you find or know of a bat roost, report it to our database
Submit your report using our online roost reporting form
Time commitment: Submitting a roost report takes about 5 minutes and is only done once per roost.
Optionally, you can sign up to monitor your roost (see below) or let us know if you are interested in having volunteers monitor the roost for you.
If you want to report a roost to our database and do not want to participate in monitoring, you do not need to formally sign up as a volunteer. You can submit your observation by filling out online roost reporting form.
What you will need to know or learn (resources provided):
How to identify a bat roost
What bats look like emerging from roosts
2. Monitor Bat Roosts for Emerging Bats
Monitoring bat roosts means counting the number of bats using a roost throughout the summer season. These surveys are called “emergence” surveys, meaning that we count the number of bats emerging from the roost at dusk to forage for insects.
Volunteers sign up for a roost and survey the roost once in June and again in July. Surveys conducted in early-mid June only count the adults in a roost, prior to the pups being born. Surveys conducted in mid-late July count adults and pups, which begin flying three to four weeks after birth. Additional monthly surveys during the entire active season (May – September) are encouraged, but in 2026 we are building program and volunteer capacity and focusing on getting surveys completed in June and July.
What you will do: Count bats flying out of a roost after sunset and record other information like weather conditions and location.
Time commitment:
Surveys occur around sunset.
Each survey takes about 1.5 hours from start to finish, plus drive time.
Minimum of two surveys required per summer (June and July).
What you will need to know or learn:
What bats look like emerging from roost
Ability to travel to and from roosts
Ability to enter data into an app, website or datasheet
Who Can Participate?
This program is open to anyone who can:
Learn to count bats emerging from a roost
Navigate outdoors safely to and from a roost site around sunset and potentially after dark
Survey at least once a month in June and July
Collect accurate data about the number of bats counted, weather conditions, and time
This program is a great fit for:
Families and groups
Anyone with a bat roost on their property
People who observe bats entering or leaving structures
Urban and rural residents
People who live near State Parks or other places that need help monitoring roosts
How to get involved
To report a roost:
Fill out the online roost reporting form.
To sign up as a roost monitoring volunteer:
Register for one of our online trainings. Trainings for the 2026 season will be offered on April 29th and 30th. Trainings will be recorded for people who cannot attend and will include information about how to sign up as a volunteer.
- What is a bat roost?
- Female bats gather in large groups during the summer to give birth and raise their young in structures called roosts. Roofs, attics, old barns, trees and bat-boxes are all commonly used examples. Bats emerge from the roost just after sunset to forage for food.
- What is the time commitment to monitor a roost?
- Each survey takes approximately 1.5 hours, plus time to drive to the site (if applicable), and at least two surveys are required per summer (June and July).
As we are building program and volunteer capacity, in 2026 we are focusing on surveys in June and July.
- What is a roost emergence survey like?
- Each survey begins approximately 15 minutes before sunset and ends around 45 minutes after sunset. You will walk to your roost site, choose a spot to watch the roost and record the time and weather conditions.
Equipment needed for these surveys includes:
A bat monitoring data sheet and/or Survey123 web form
Scratch paper and/or a tally counter for counting bats
A watch, phone or other device with a clock.
Recommended equipment includes:
A chair or blanket to sit on so you can watch comfortably
A flashlight or headlamp
Bug protection
Protective clothing (long pants and sleeves, etc.)
Volunteers will be responsible for:
Learning where their roost is located (with assistance)
Navigating to and from their roost before and after the survey
Evaluating if weather conditions are suitable for a survey and collecting basic information about the weather conditions
Counting all bats seen exiting the roost and submitting the data to our database
Volunteers are also be responsible for notifying landowners (for roosts on private property) or State Park staff (for roosts in state parks) when surveys are planned.
- How does this project help bats?
- Data from these projects will help us understand how bat populations are changing through time in response to conservation challenges. This survey will help us establish baseline information about summer bat populations in Minnesota.
Roost monitoring is an effective way to collect population data on bat species that can otherwise be difficult to observe. Understanding the distribution and density of summer maternity colonies across the state can help us keep Minnesota’s bat populations healthy.
- Why do bats matter?
- Bats are a part of a diverse Minnesota ecosystem. Minnesota’s bats are strictly insectivores (wildlife that eat only insects), and they can consume their body weight in insects each night. They feast on mosquitoes and a host of agricultural and forest pests that damage crops and impact forest health. Bats benefit Minnesota ecosystems in many ways, yet they are facing severe threats that are reducing their populations throughout the state.
- Frequently asked questions
- Can more than one person survey at a time?
Yes! Some roosts actually require more than one observer so that at least one person can be watching each roost exit at all times. Some smaller roosts such as pole-mounted bat boxes only require one or two surveyors. Larger roosts with multiple exits such as old barns may require multiple observers. For all surveys, there should be one person to monitor each roost exit.
If you want to bring other observers during your survey that is allowed, just make sure they are able to stay quiet and do not interfere with anyone counting bats. At least one person in the group must be registered as an official DNR volunteer in MyImpact.
What if I want to survey, but there are no roosts near me?
We are hoping to get reports of more roosts throughout the summer and will continue this project into future years. Sign up to receive our newsletter updates to stay informed (enter your email in the box at the bottom of the webpage).
You can also install bat roosts on your property to encourage bats to roost there! For guidance on how to maximize bat box usage, review our Guide to artificial bat roosts or watch our Minnesota Outdoor Skills and Stewardship a href="https://www.youtube.com/watch?v=cP3MFv-Qbi8">How to maximize your bat box seminar.
Is surveying or being that close to bats dangerous?
While being outdoors near flying bats is not dangerous, you should avoid standing or sitting directly under the roost to avoid guano (bat excrement) that falls out of the roosts. You should also not pick up any live bats you see on the ground, or touch guano piles below a roost. To maximize safety for everyone, do not shine lights into a bat roost.
I want to get the bats out of my roof/attic/etc. and stop them from coming back. Do you still want to know about that roost even though I plan to stop bats from using it in the future? How can I do this without harming the bats?
Yes! We still want to know about your roost even if you plan to exclude the bats. Conducting at least one roost survey to count how many bats reside in the roost before they are excluded from the building is very helpful information. We also have resources about how to conduct safe bat exclusions and how to place bat roosts on your property so the excluded bats have somewhere to go. See the resources section below for more information or Managing Bats in Buildings-Alberta .
- More information about bats