Interested in Bat Houses but Overwhelmed by the Options?

Want to put up a bat house but are confused by the options? No worries, I’ll give you some tips to help you figure out which bat house is right for you, and which ones you should avoid.

Bat houses and their plans are fairly easy to find but unfortunately most of them are poorly designed. The first thing to do is find a bat house that has been certified by Bat Conservation International (BCI). BCI is a non-profit organization based in Austin, Texas that focuses on the worldwide conservation of bat species. BCI has collected over 10 years worth of research to determine what factors makes a bat house successful. Everything from size of the house, width of roosting spaces, where and how high to mount the house, and what color to paint the house has been evaluated.

A wonderful compilation of this research is “The Bat House Builder’s Handbook, Completely Revised and Updated” published in 2004. This book is readily available online for around $10 and includes plans to build your own bat house.

If you don’t want to build your own bat house, you want to look for one whose design has been certified by BCI. The certification process ensures that the design of that particular bat house adheres to the research findings collected over the 10-year period mentioned above.

You can find a list of companies that sell certified bat house on BCI’s web page. The BCI certification seal should also be found on any webpage that sells BCI certified bat houses.

Once you’ve found a source of BCI certified bat houses, you’ll need to decide on the size. Generally speaking, the larger a bat house the better. When bats choose a house, they’re looking for specific temperatures. The bigger a bat house, the more variation there will be in temperatures. For example, the bottom of the bat house may be slightly cooler than the top of the bat house. These variations, or microclimates, offer bats more roosting options and enable the bat to move around in the box to cool off or warm up as needed.

The most common design is a rectangular wooden box that is open on the bottom (conduct a google search on “bat house” to see this design). The size of the box usually varies between one- and three chambers however you can occasionally find larger houses that have upwards of five chambers. The number of chambers of a bat house simply notes how many divisions are inside the box. Wooden bat houses are a good “starter house” as they are lighter in weight; which makes them easier to install. These types of houses are usually cheaper, beginning around $30 and increasing in price as the number of chambers increases. These houses need to be inspected on a yearly basis. Any seams that have pulled away will need to be re-caulked and any painted areas that have worn will need to be re-painted. Two great sources for bat house maintenance are The Bat House Builder’s Handbook mentioned above and an instructional manual available for FREE through a company that sells bat houses (scroll down the page to click on the link that downloads the .pdf manual). The average lifespan of a wooden bat house is 5 years.

If you’ve been around the block in terms of bat houses and are looking to add additional bat real estate (or a house that has a longer lifespan than the wooden bat houses), you might be interested in a house that has a larger capacity. These designs can have outer shells of steel, plastic, and other materials. The advantage to these houses is they have a larger capacity (often holding hundreds of bats), have a longer lifespan, and require less maintenance. The disadvantage to these houses is that they are often more expensive ($100 and up) and can weigh around 30 pounds, requiring at least two people for the installation process.

For community or colony-sized bat houses, hotels/mini-condos/condos may be more up your alley. These houses are designed to hold thousands of bats and are often used when known bat roosts are removed or destroyed (for example, an old barn needs to be torn down). This type of structure is perfect for nature centers, conservation areas, and areas with known large colonies of bats. Plans for these types of houses are available on the internet but require quite a bit of construction know-how and specialty equipment. Supplies will cost between $1,000 and $2,000. These houses are available pre-built from companies that will drive them to your project site and install them for you. Costs range from $3,500 for the smaller condos to $5,000 for the full sized condos.

In summary, make sure your bat house/bat house designs are certified by BCI. If you’re purchasing a pre-built bat house, it should come with instructions for the preparation, installation, and maintenance of the bat house. Once you’ve met these two criteria, choose the largest bat house/design you can afford and/or is appropriate for the site where you’ll be installing it. If you’re tentative about your first bat house, go for a three-chamber wooden house as it is less expensive and you can easily upgrade to a larger bat house at a later point. If you want to install a bat house and never worry about it again, go with a non-wood material such as steel or pvc plastic.

If you have any questions about a bat house you’re considering purchasing, call the company selling the bat house. The person you speak with should be able to answer all of your questions. Good luck with your bat house adventures! Should you have any questions for me, please send them to me at VespersAfterMidnight(at)gmail(dot)com. I am happy to further expand on any information listed above.

You study bats? The ones that fly? Why?!?

You study Bats? The bats that fly? Why?!

I cannot count how many times I've been asked this question. The inflection used by the speaker when asking "why" varies between curiosity and revulsion. It never fails to make me smile.

My work with bats started in 2002 in the southwestern US. I was working as a wildlife biologist and was introduced to a husband and wife team of bat biologists.  Seriously.  There really are people that study bats for a living.

I quickly became enamored with bats.  Their nocturnal lifestyle, ability to fly, and echolocation set them apart from other animals.  While I found the animals themselves to be fascinating, the act of studying them was equally so.  I spent countless hours during those first years conducting mine surveys, mine outflight counts, and mist netting surveys.  Bats became an addiction and I used my accrued vacation time to attend conferences, workshops, and radio telemetry studies.  Other people thought I was crazy.  This opinion has not changed much.

A few years later I decided to return to graduate school to pursue my master’s degree.  It seemed only fitting that bats should be the focus of my research.  I moved cross-country to the east coast and settled in a small town in the Appalachians.  My research over the next few years focused mainly on subterranean habitat (places underground that bats used) such as abandoned coal mines, caves, and other man-made holes in the ground. 

After earning my degree, I found a position that enables me to combine my love for bats with research and education.  I feel lucky to be able to do what I do.  And, of course, to this day, I continue to be asked, “You study bats? Why?!?”.  

Why the name "Vespers After Midnight"?

The name of the blog is a throwback to my earlier years. Vespertilionidae (pronounced Vesper till ee on ih day) is the largest Family of bats in the United States, representing over three-quarters of the species found here. The Family is commonly referred to as the evening bats.

When I was studying Mammalogy as an undergrad, I was able to remember Vespertilionidae simply because vespers are evening prayers.  See the association? Vesper, evening bats? A lot of biology is memorization. Word associations always helped me to remember scientific names – the crazier the word association, the more likely I was to remember it (ask me sometime how I remember the scientific name for elbow bush).

As bat work tends to begin after sunset and often continues well past midnight, “Vespers After Midnight” seemed to not only be a fitting description of my work, but also serve as a framework for the tales I hope to tell here.