CEDAR BAT HOUSES!

http://www.fws.gov/northeast/white_nose.html

Boy this is pretty serious- first bees (which are still dying in record numbers) and now bats. Bats are dying by the thousands in Northeastern caves. The immediate cause is not known. A possible secondary infection, a white fungus that is on the noses and body parts of bats is apparently tied to the initial infection.

Please check out the link above for further information. This is really serious, as bats account for a significant part of the insect population control. It appears that this disease is affecting microbats, DEC officials are anxious to find out the cause. The more microbats lose habitat, are disturbed in caves during hibernation, the more of a challenge these insect eaters face.

Credit: U.S. Fish and Wildlife Service

Photo by Robert Shallenberger/U.S. Fish and Wildlife Service or USFWS photo (if the photographer is known)

USFWS/Elkins, WV (if originating office but not the photographer is known)

Below is a very interesting article on the subject and impact of this mysterious disease. Please check it out.

http://www.post-gazette.com/pg/08118/876982-85.stm

I'm getting my house off of the loft and up on the pole. I'm checking it over for cracks, gaps and anything out of the ordinary. Now is the time to get some good silicone caulk. I use the black silicone and seal it up. It dries fast and moves with the house.

While the end of winter and beginning of spring are great times to put up a house, frozen ground or wet ground can be troublesome when putting a post in. Fall is also a great time to prepare your house for spring bats. If using a post, fall is a great time to get your post hole dug and cemented in. You can also put in a pivot post to make it easier to get the house down in winter.


Now, not all bat houses are the same and many that are for sale in most home centers, ebay and the internet are junk. I say they are junk because they are made to look pretty, but many times have chambers that are much too large for any bat to occupy. A proper house should have 3/4" chambers and really not be much larger than that. I am not as concerned with the size of a house, for Europeans have used small bat houses successfully for little browns and big brown bats for years.
A well constructed bat house will be much more suitable for bats and be one they come back to year after year.

I get this question a lot on ebay, probably more than any other. Customers describing their property, the bats they see at night flying around, but cannot decide on what house to buy. Always buy within your budget- and buy from someone that sells houses that look well constructed.



I suggest buying a house that you can afford and one that you will be able to easily hang. It is important to buy one that suits the size colony of bats you have. You really can't go too small, as you can always add houses later or upgrade over winter. And, its been proven that small houses work. Large houses typically have a better occupancy rate due to being larger and more visible and holding heat better. Winter is also a good time to perform maintenance on your bat house- I'll get to that further down the page.

Consider that single chamber houses are lighter, may hold less bats and usually hold less heat- so its a good idea to paint them black in northern climates. I will get into maintenance soon, but normal maintenance is as easy as re-caulking once a year.

Ok- below is a picture I took of one of my own 3 chamber houses in the process of getting painted. I used just a simply small can of Rustoleum satin black water based paint. I picked it up at Home Depot for $5 bucks. One little can and a cheap $.99 throw away brush will get the job done. My bat houses are built with rough cedar. I don't sand it as a water based paint will raise the grain anyway. I just spread it on with a brush, its completely dry in an hour.



If you are considering a single chambered bat house, I suggest a single chamber being mounted flush against a building, home or shed to help retain heat. This isn't critical at all, but it does help. Also facing the bat house towards the southwest so it gets more direct sunlight is preferred.

If you are considering a 3 Chamber house, they are considerably larger, weigh more, hold more bats, hold heat better. So if you have a large colony, a 3 chamber is probably right up your alley!

Construction is an important factor when considering a bat house. I do not believe in using plywood, I don't care if you paint it or not, it will warp. If it doesn't warp, it will delaminate. Just go to any Home Center (you know the ones) take a look at their plywood. Its bowed, splitting, peeling apart. Put that outside in the weather, game over. My bat houses are constructed out of 5/8" to 3/4" cedar. Its a stable wood that handles the elements very well. It expands and contracts with moisture without warping and distorting. So keep that in mind when shopping for a bat house.

Remember to always be careful mounting your bat houses and don't be a Hero. Ask for help if you think you need it. Ask a neighbor or friend to help you, then offer them a beer. You can kick back and relax, talking about the bat house and the good deeds you have done.

As discussed above, no plywood. Plywood houses aren't going to last in blistering heat, rain and wind. I was at a nature preserve last year with my son and we ambled upon a few bat houses. They were painted green, not my choice, but painted none the less. They also had this green mesh lining the inside. The houses were made of plywood. Now, all wood moves... that being said, the plywood buckled and had openings that had to have been 1/2" wide. Even more upsetting (I wasn't really physically upset mind you, I'm no wimp) was the mesh all hanging down. It was a bat trap pure and simple. Each house was the same way. Only humans would think that bats living for thousands of years need help climbing into a bat house. Remember, mesh kills. No Mesh.

But there are other things to consider too. If you are looking at bat houses with more than one chamber, buy one that has chambers set in dados. I prefer this. Its not something people do unless they have the table saw or router table to do it. Dados are grooves in the wood that prevent shifting and movement of the chambers. It keeps the house square and adds significant longevity to the house.

You want the chambers to be set 3/4" wide. This is really important. I went to a home center, one of the big ones and found a bat house that I could stick my full hand all the way up to my wrist. I thought, this is the biggest Wasp House I've ever seen. If the manufacturer was thinking bat house, it was soon to have a nest of Paper Wasps that no bat would ever go in to.



You don't want them any wider than that. I've seen bat houses littered on ebay with 1" to 1.5" chambers. Those aren't bat houses, they are Wasp houses, or soon will be one. One reason to choose the right chamber dimension is bats like tight, warm places to huddle together. They also like the safety aspect that predators will have a hard time getting to them. You may think 3/4" is too small but they can easily get through an opening the size of a quarter.

Another issue is insects. Chambers over 3/4" are a favorite of wasps as discussed. Paper wasps will build nests in the house routinely, but even more so in houses with too large a chamber. A house infested with wasps will not be a location bats will be comfortable in.

Consider the construction detail as well. I use galvanized 15 gauge nails, so they don't rust out. That isn't an option, that is a requirement! Nails are fine to use in a house, some think only screws should be used to construct, but toenailing them in is very strong, especially when laid on a bed of caulk.

Speaking of caulk, make sure the house is caulked! At least the top, but better if the sides are done as well. As I will get to in maintenance, caulk when it sets helps keep the house together and most importantly, keeps out drafts and moisture.

A well constructed house will be made of cedar, either Western Red or Northern White Cedar. A good pest controlling wood, that is ideal for being outdoors. If you buy a house with more than one chamber see to it that they use dados or slots to hold the chamber partitions and that it is toenailed. Also, caulking the house not only holds it together, it keeps out drafts and moisture.

In finding a suitable location, you should look for an area where you will get at least 6-8 hours sun exposure, be close within a ¼ mile of water, woods, or other areas where insects congregate.
If you already have bats, you probably have the aforementioned criteria.

Recommended mounting height is 12-14 feet from the ground. A common question I get, can I use a tree?

Here is my neighbors bat house. He wanted it up on the dead tree, a lot of bats live in those woods. A little pruning is in order, but its about 14' up. Problem is, he has had no bat activity. Vines and bush that scale this dead tree are choking off the house. Lots of bats flying around in those woods, but none feel safe enough to move into a bat house on a tree.



I do not recommend it, but yes you can. I don't recommend because a lot of trees are too dense, shaded or out of view. An unused telephone pole, house, building, shed, or pole is better- If you have a telephone pole be aware its owned by the telephone company. The issues about using a tree, the house needs to be mounted free of any branches, and should get sun exposure to stay warm. Trees make it difficult because a full canopy shades the house, may create a predator issue and may have interference around it. Many people place wooden posts in the ground (4x4 or glued/screwed 2x4s pressure treated), mount to the sides of their house/building, or use a steel post. Check with your local hardware store/home center for suitable wood or steel posts. If you use a steel post, you'll need to buy inexpensive mounting brackets. I have found it best to dig a hole 2-3 feet down and with help, place the post and bat house in the hole. Then fill the hole with stone/Quickcrete or Sackcrete add water and mix. You'll need to support the post so it doesn't tip, but once cured its a good solid structure. If you decide to use a pressure treated post or pole, you will need help. Get your neighbors together for a 1/2 hour, have the hole dug and supplies handy, then afterward crack a cold one and marvel at your work. You may find your neighbors wanting to be just like you.

A remarkable compliment of great vision, hearing and smell let the bat find the nooks and crevices that they love to investigate. You wouldn't think flying around at an erratic pace they'd be able to see well, but they are designed by God to devour the smallest insect, find the warmest home and rear a single pup. Great little mammals these bats are. My suggestion, place the bat house where they can see it, out in the open. Bats have great vision (they are not blind as the saying goes) and will find it if it's accessible. Bats look for areas to roost that hold heat, they are not attracted to chemical attractants. That is why you will find bats in attics, behind shutters, under eaves and other safe warm locations. Please also keep an eye on pests. While I make my bat houses to be less than ideal for wasps, yellow jackets and other menaces, those pesky buggers will build nests anywhere, ideally warm places. So, if you see a paper wasp nest or other, remove it quickly without chemicals. Painting the outside of the house also prevents paper wasps from chewing the wood to build their nests. They love the fine hairy wood fibers of cedar when left exposed. Should you find a wasp nest in your house remove it, but do not use chemical sprays, a stick can work well but don't injure any bats.

Hopefully you will have plenty of bats flying around your property and be enjoying the outdoors with less bugs. All those bats flying in and out and the wear of weather and time, mean your house will need a little upkeep.

After the bats leave the house for their winter hibernating areas like, caves, under bridges, flying south, you may want to consider taking the house down. This may seem like a lot of work, but in the long run, its better off. Where I live in Buffalo, our winter storms, high winds, driving hail and other factors like freeze and thaw, would decimate a bat house in a few years... leaving an unoccupied eye sore. Just taking the house down in the end of fall will result in a product that lasts so much longer.


Its fine to leave it up, but taking it down will allow you to check it over. Recaulking if necessary and setting any screws and nails that may have worked their way loose. Removing any old wasp nests or wasps still on a nest (careful). Inspect the overall house condition and possibly add another coat of paint. Winter is a great time to perform these simple things to get the most out of your bat house. With simple care, your bat house will last a long time. Painting, caulking and sealing out drafts will make your house a roost bats will enjoy for years.

If you put up your house and don't get any bats, do not get discouraged. I know, easier said then done. Houses can go unoccupied for a season or two before they are accepted. Yes, that is true. The Florida Bat Conservancy indicates that a bat house can even go several years. Its very possible. Bats like to use the same roosts over and over. If you find after year you have no guano under it, don't worry. Bats may have a great roosting area nearby that gives them greater protection, bug population may be better where they are too. I found that bats would use my house briefly as a resting area between hunts. Then just before dawn they would make a break for their roost areas in our woods. That is ok, I felt that they used it for what they wanted to use it for. Usually, houses are occupied within 4-8 months on average. To encourage success, mount the house where it can be seen, where it will receive at least 6-8 hours of sunlight, away from predators, and near areas of insect population. If you do not get bats within the first year, you may want to try moving the house to another location. However, I caution moving a house too soon. My bat house took a couple years. My first location was too shady. The second location seems much better- out in the open, facing the southwest. Bats (little brown) are active within the first 3 hours after sunset and in the pre-dawn hours. Most of the time inbetween is spent roosting and digesting their meal. Make sure your house is in an area where it will be noticed. Most houses that go unoccupied are due to lack of insects or amount of insects in the area, lack or protection from predators or improper placement of the house. By offering a roosting site, they will pay you back with thousands of insects consumed.

I was a little hesitant to put up a pivot post, only in so much as the amount of work it would entail. But honestly, it wasn't too bad. A couple bags of pea gravel, a bag of quickcrete cement, a shovel to dig a deep hole, some pressure treated or cedar boards for a base and some ridgid electrical tubing and you're all set.

Check out the attachment of how a pivot post can help you get a bat house up safely! Its so easy to put up and down for cleaning, you'll really like this idea!