Final Lab Packet
The purpose of our “Bat House” project is to gain a greater understanding of bat
habitats. We decided to study bats because they seemed interesting when we saw them
flying around the sky one night. We hope to determine any correlation between the
location of the bat house, and the number of bats that will inhabit the house. We believe
that the denser the coverage is and the further the houses are away from people and
lighting, the more bats will inhabit the house. We plan on successfully building our bat
houses, locating them, and observing them to determine if the factors mentioned in our
hypothesis are indeed true. Our hypothesis is that bats will prefer houses located on man
made structures instead of houses located in natural areas, like on trees. The relevance of
the data we will collect will be useful information to farmers as well as others interested in
attracting bats for the control of insects.
Relevance to Research Question
As we just mentioned bats feed on insects such as mosquitoes and plant eating
cucumber beetles. Over time farmers have become more aware of bats as a method of
insecticides. After looking at many sites on the Internet as well as countless books we
were able to find a variety of bat houses, and we then researched them to find the best
house for our project. We chose a bat house recommended by the Bat Conservation
International. This plan came not only with a recommendation, but it also came with
testimonial regarding its success. Although, in our research we came up with many
bizarre facts regarding bats, much of the information centered around bats as animals, and
not the habitats that attract them. Although it made obtaining useful information on our
project difficult, it made our group feel that we were studying a topic with little public
The first step to the experiment is to construct four bat houses. The houses should
be made out of either pine or western red cedar, marking sure not to use any type of
treated wood or plywood. A plan for these houses is attached to the back of this packet.
Once the houses have been built, select four locations for hanging the houses.
Two of the locations should be in natural areas (e.g. trees) and the other two should be in
manmade areas such as on buildings or under bridges. The height of the house should be
at least fifteen feet off the ground. Exact height is not of vital importance, as long as the
house faces east and catches a lot of morning sun, because the morning sun will help keep
the house warm for the bats. The easiest way to hang bat houses is to use rope and tie
them to tree limbs or tie them to pipes or windows on buildings. Be sure to use nylon
rope so that it will not rot, causing the house to fall.
Measurements of the number of bats in each house should be taken weekly. Every
Friday at around 1:30pm, go to the various bat houses and count the number of bats in the
house. One should not take measurements at night because bats are nocturnal and will be
awake when it is dark. Record results in a data table like the sample attached to the back
of the packet.
To ensure a non-biased experiment, we plan to make sure that the only variables in
the experiment are the locations of the houses. The same type of wood will be used for
each house and the dimensions will all be the same. The tar on the roof will be the same,
as well as the glue used to hold them together. They will all face the same direction, and
we will check them all within about a half an hour of each other.
We do not yet know if this experiment is statistically sound because we need some
data before we can run tests to find out. We have, however, designed the experiment as
best we possibly could using the data we have collected through research and talking to
10/3 – Build houses and get them ready to hang.
10/9 – Hang bat houses (one in a tree across from Peabody Hall, one on the back of
Peabody Hall, one on the roof of Boyd Hall, and one in a tree outside Boyd Hall.)
10/16 – Check bat houses for the first time and record results. Check each Friday
thereafter as well.
11/27 – Check bats houses for the final time.
11/27-12/1 – Further research due to anticipated results of study.
12/2 – Final presentation.
12/11 - Final lab manual turn in.
1) Western Red Cedar or Pine
2) Plastic Sheeting
3) Tape measure
6) Nails (various sizes)
8) Table saw, chop box, jointer, planer, sander, drill, etc
10) Nylon Rope
11) Eye hooks
12) Bat house plans
14) Tar Paper or Tar
17) Eye protection (for checking houses Safety First)
19) Clipboard and data sheet
20) Assorted hand tools
21) Weather Stripping
For class participation, and our presentation we have a few things in mind. First,
we plan to give a brief lecture on the information we learned about bats. Included in our
lecture we plan to tell the class our experiment and show them a bat house that we built.
After our 10-20 minute lecture we will divide the class into five groups (each of us leading
one of them). We then will take each group to a different bat house and show them first
hand how we collected our data. Shortly after this has been completed we will meet back
at the classroom and discuss our findings. We then, as a group, will reveal our results
with our experiment, followed by a discussion on why we got the results we did and
possible solutions to problems and ways to improve our experiment.
Note: Due to weather concerns (rain), we were unable to go outside. So instead of going
outside, we had arts and crafts time. We had the class construct paper bats and gave the
best design candy.
Initial Plan for Analyzing Results - 10/6/98
The data that we will be recording for our results is the number of bats in each
house. We will observe all five-bat houses once a week on Friday afternoon. We are
planning on checking the houses during the day because bats are nocturnal and hopefully
will be sleeping when we come to view through the plexi-glass.
We plan on explaining and showing our results in both a table, and a simple bar
graph depicting the number of bats in each house as the weeks go by. Questions which
have arose are what if no bats live in our houses? If this is the case we will try and
determine why, and discuss possible solutions to the problems our experiment
encountered. Suggestions for further research are possibly looking up more information
on the Internet, but more importantly are that we are going to try and talk with the person
in charge of the bat houses Hueston Woods. We will hopefully be able to learn more
about our experiment by looking at what others have already done. By doing this we
hopefully will avoid mistakes in construction of our bat houses.
Further Background Research
As was noted in the timeline, it became apparent that no bats were going to move
in to the houses. Because of this, further research was conducted in order to find out
more about bats in the United States, specifically in Ohio. Research was also done to
examine possible causes for the lack of bats.
Bats in General - Bats have several basic needs concerning food, roosting, and
climate, and a lack of predators. They live in a variety of habitats such as forests,
riverbanks, farms, urban areas, etc. Some species are more particular about their roosting
sites, and are therefore more limited by environmental factors. And obviously, in order to
flourish, bats need a large amount of food near their roosting sites. In addition, they need
to accumulate enough energy in their fat reserves to survive the winter months.
Bats need two basic kinds of roosts to survive. An internal roost is more stable
and permanent and tends to be very traditional. Such a roost would be used for as a day
roost, a maternity roost, or even for hibernation. An external roost is less permanent and
provides less protection. Such a roost is used as a day or night roost, but is usually less
The climate in which these roosts are located is also very important. Bats prefer a
high temperature and humidity, a certain amount of light for feeding or lack of light for
roosting, and protection from the wind and predators. Depending upon the climate in
which they live, they may hibernate or migrate to escape freezing temperatures of winter
weather. Hibernation requires a protected place that is humid and just above freezing
temperatures so that the bats use as little energy as possible throughout the winter months.
If disturbed too many times, the bats may die because they have used up the fat reserves
accumulated during the summer and fall.
Bats in the United States – Over 40 different species of bats live in the United
States. There are many more species around the world, but they live in tropical regions.
Of the 40 species that are in the United States, the majority resides in the southwest
because they like the warmer weather. They prefer the warmer weather because they need
vegetation and warm places to live. If they live in the cold regions they hibernate during
the colder months or migrate to a warmer place.
The species are spread out around the United States. Of the 40+ species, 28 live
in the southwest, 10 live in the northwest, 9 in the Midwest, 13 in the south, and 10 in the
northeast. Some species live in more than one region. Also, there are six species that live
all across the United States: Little brown bats, least brown bats, silver haired bats, big
brown bat (also known as barn bats and house bats), red bats, and hoary bats.
Bats in Ohio - Only about eleven species of bats live or are suspected to be living
in the state of Ohio. Of those eleven species, only two are actually common to the area:
the little brown bat and the big Brown bat. In general, bats living in Ohio and in the
Midwest feed solely on insects and depend mostly upon in-flight feeding to catch their
prey. As with any type of bat, they devour an immense amount of food every night and
need a habitat abundant with insects to stay alive.
The little brown bat in particular is located throughout the United States, but is
more common in the northern parts of the country. It is a colonial species which
hibernates in the winter, and it can exploit a wide variety of habitats and roosts. Although
it has been found in alternative habitats, the little brown bat prefers to roost in a dark place
near to water. As with many species of bats, the little brown bat depends on insects over
the water of a pond or stream for food.
The big brown bat is also found through the United States and North America. It
lives in colonies during the summer and hibernates alone during the winter. it roosts in a
variety of places, but seems to prefer the shelter of buildings and bridges. It’s roosts are
very traditional in that it tends to return to the same roosts from year to year. It is also
quite unique because it prefers much cooler and drier climates than most bats for
hibernation. Regardless of roosting choice, it’s feeding sites are non-traditional and
Actual Results - 12/10/98
Unfortunately, no bats ended up moving in to any of the four houses. What a
surprise! Actually, after some of our further research on bats and their roosting habits,
this was not unexpected. We will be discussing this research in the next section. Attached
to the back of this packet is a chart and graph of our lack of data. Also included are some
charts and overheads from our presentation explaining where various types of bats live in
the United States.
Reasons Why There Were No Bats
There were several factors contributing to the lack of results in the form of no
bats. There are the habitat preferences of bats and the natural environment of Oxford that
contributed to our results. First, bats tend to go into hibernation during October and
November to avoid freezing. Our first hanging of a bat house was on 10/9/98, therefore
the possibility of our group finding bats was greatly diminished.
Second, bats enjoy humid weather and a lot of water to provide them with a food
source, specifically insects. Oxford is a fairly dry area, and even though Hueston Woods
has a reservoir, the bat houses are located a good distance away from it. Also, the
weather around Oxford recently has been very unpredictable. This would wreak havoc
with a bat’s metabolism, and they would not survive the winter. Bats require cold near
freezing temperatures in order for them to extend their fat reserves, so the warm weather
is not a good environment for bats getting ready to hibernate. Our houses were not even
designed for bat hibernation. They were designed primarily as a day roost for the bats.
Third, there is a lack of physical features that are conducive to bat hibernation (eg
caves). Only a few species of bats are common around Oxford to begin with, and the
stated factors do not aid in the appearance of bats. Also, half of our bat houses were
located in trees. According to a study run by Bat Conservation International, it was found
that bats would not find a house mounted in a tree until 255 days later on average. The
bat houses mounted on buildings were not found until an average of 71 days. This number
does not bode well for us in any way. Our survey duration was a little less than seven
One final note was a discovery that contradicted initial research. We found that
bat houses in our area were under the recommendation that they should be painted dark to
gather heat. It was found initially that bat houses were supposed to be kept clean and
without any manmade scents, paint being one of them. All of our houses were untreated
pine with tar roofs. These factors combine to make Oxford a poor location for the study
of bats. Unfortunately, we did not uncover any of the previous research when the project
was being designed.
Our study of bats was not a total disaster. As a group, each individual did learn a
significant amount of new information about the habits of bats. Our group was not able to
contribute any new findings to the world of science, but one lesson we have learned from
this project is that experiments do not always yield the best results (or in our case any
results at all). Science is all about trying new things, and inevitably failing at some point.
Our group failed to achieve results in our specific project, but did learn a great deal about
the world of science in the process. And who knows? We plan to leave the houses in
place for the duration of the second semester. Maybe bats will eventually find the houses
and have a nice place to roost in the warmer months. Only time will tell.
Barbour, Roger William. Bats of America. University Press of Kentucky, 1969.
Bowers, Terrell. “Bats Bombs Away!” Boy’s Life, vol: 88n4, Apr 1998. P.11.
Marini, Richard A. “Bat Haven” Popular Science, vol:252n4, Apr 1998. P.30.
Feder, Henery M. Jr. & Nelson, Randall, & Reiher, Herpert W. “Bat Bite?” The Lancet,
Vol:350n9087, Nov 1st, 1997. P.1300.
Hardman, Chris Makckey. “Going to Bats” Americas, vol:49n6, Nov/Dec, 1997. P. 3.
Anonymous. “Batty Friends.” Environment, vol:36n8, Oct, 1994. P. 24.
Tuttle, Merlin D. “America’s Neighborhood Bats” vol:42n6 Oct, 1997. P. 39-51
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