Bat House Forum

[JR0835]

I just finished this nine-chamber bat house. It weighs 59 pounds and has four nurseries for baby bats, two chambers for adult batchelor bats and the rest for family bat groups.

[Terry Lobdell]

Great looking bat box! I really like the stencil job too!

[JR0835]

I designed this bathouse, drew it in AutoCAD on my computer and have had request for the plans.

The nursery chambers are the ones that are sealed off at the top and 12" down each side. I added one more than is shown here. Other chambers are open to the top. Sealing them off keeps the temperture very high, in the 95 to 100 degree range that baby bats like.

[JR0835]

Interior panels prior to assembly.

Exterior is flat black.

[Terry Lobdell]

Great design! Thanks for sharing! I will be looking forward to hearing about how many bats you get using it!

[William Bagwell]

Wow, it's huge! Could not tell from just the picture just how large it really is. Going to 'borrow' your idea about sealing off a couple of the middle chambers. Working on a seven chamber with very thin baffles myself and that sounds like just the ticket to make up for lack of mass.

[JR0835]

It is 26" x 40" x 10" deep, weighs 59 pounds and should hold 585 bats. The nursery chambers are centered in the bat house, away from exterior walls and roof, so heat from surrounding bats will keep it warm. The three chambers that are shown closed at the top are also closed 12" down each side to trap as much heat as possible. Remaining chambers are open to the top.

[cloudman75]

Great looking bat house and drawings. I built a bathouse for pups back in Nov. 2010 and have photos posted on here. I closed off two chambers at the top and sides and cut holes in the baffles so the little pups could travel in an out without going below. I had no takers in 2011 as the bats used the same old house
again last season. I built an attic over the pups chambers which was a mistake as it attracted wasps. I am hoping for some use this coming season.
My house did not look as nice as yours, but I had a few adults use it this year, but no maternity colony.Keep us posted this spring when the bats arrive.

Frank

[JR0835]

The bats are already here. They didn't leave. (Winter has been cancelled due to a lack of interest.) My existing bathouse is full and I want to replace it with the new one. Not sure if I should put the new one up beside the old one or just take the old one down while they are still in it and put up the new one. Will probably lose a lot of bats either way.

[cloudman75]

I just picked up on your location in deep south Tx. You probably have freetail bats which will stay around because there is something to eat in winter.
I have a few here during warm spells in winter, but they leave when it gets cold at night and the bugs go away. Was your other bat house a dark color also?
I would have thought a lighter color would be required as my bats get too hot here in summer. I really have a hard time with my 5 chamber large house as it weighs 45 lbs. I built it out of plywood and it is on a 1 1/4 inch schedule 40 galvanized water pipe. It takes two good men and one gorilla to put up in the air.
Will be anxious to see some photos of your bats so please post some on the forum for us winter bound folks. BTW, how did you determine that your large house would hold 585 bats? That would be of interest to many of us I would think? I think some of the store bought houses over state their house capacities.

Frank

[cloudman75]

Terry,
I estimate a much larger capacity for this 9 chamber bat house. Would you use your estimate to see what you get as mine is huge. How is the recovery going? I could have made an error in my estimate so would appreciate your input.
I am having thoughts of putting all my bat houses under one roof on a board similar to what you did. My backyard is getting to look very cluttered, but the bats don't seem to mind. (mounting board in mind)

Frank

[Terry Lobdell]

Frank,
I came up with an estimate of about 800 mothers plus pups without pups falling out.......

Keep in mind my figures are based on my experience with little browns......I have no experience with freetails.........

Years ago I had 75 mothers in a 2 crevice box with only 3 square feet of roosting area (figuring just one side of the baffle)

That comes out to 25 mothers per square foot.

I had 5 pups fall out and die even though I had mounted a 2nd box nearby when I saw how packed the first one was.

So.......I thought a safe number would be 15 mothers per square foot as a conservative estimate to ensure enough space.......

Kent Borcherding always said that downed pups was almost always a case of over crowding........I have to agree with him...

I also think if both sides of the baffles are roughened it helps keep pups from falling........

That is another reason why I have gone to rough sawn lumber for all my baffles.....

For JR's bat house I figured 2' x 3' = 6 square feet per baffle x 15 bats per square foot = 90 bats per baffle.

9 baffles x 90 bats per baffle = 810 bats.......I rounded it off to 800........

If both sides of the plywood are roughed well it could hold more, if one side is left smooth then there would be more chance of pups falling if it gets really packed.........

Overall I think it is an excellent design that is going really fill up if they are already packed int he single crevice box at that location!

My recovery is going frustratingly slow, thanks for asking! I have a limit of only 30lbs that I can lift and cannot bend over for 6- 9 months.......I am doing some bat house work this winter but it is going really slow........I have a lot of projects planned for this summer so I will probably have to get some help if I have any chance at all of completing them.........

[JR0835]

Terry
The average size of the baffles is 2' x 2' @ 15 bats per sq.ft. would be 540. The sidewalls are also roughed up for roosting area and that will add 45 more bats. Total would be 585 bats. That's what I came up with based on the capacity of the old single cell bathouse I have. Both sides of the baffles are roughened. In the three nursery chambers, the total area is 8 sq. ft. and I calculate 24 bats (females + pups) per square foot. That would add another 72 baby bats. I came up with an actual total of 657 and thought that is probably the maximum I could expect.

This YouTube video is from a place about 200 miles north of me.
http://www.youtube.com/watch?v=ZsH3ZAwXQS8

Jack

[JR0835]

Final Installation photo. Old single cell bat house is mounted to the right of the new house. Small bachelor bat house is mounted on the left side of the large house.

bat-11-a.jpg (45.04 KiB) Viewed 288 times

Jack

[cloudman75]

Thanks for estimate Terry. I think the formula I posted at 4 cubic inches per bat based on the cavity volume is not enough space for females with pups.
I can't remember which site I copied that formula from but they used only 3 cubic inches per bat.
Last year when I rmoved the large 5 chamber and put up three new houses, the females all used one house and were overcrowded. As a result I lost some pups which documents in my mind what Kent and you had posted about overcrowding. In general, last year was not a good year for me with bats which I think was a result of changing their enviorment. I plan to put the big five chamber back up for this season. I let my vitamin D, B12, and iron get low so had iron
deficiency anemia a few weeks ago on my check up. I have had no energy or desire to fix anything recently. I am taking iron as prescribed by my doc along with other vitamins and hope to be in a mood to get to work soon. I go back in March for a re-test. You need to be careful and not re injure yourself.
Freetails I have are about the same size of little browns. They should really enjoy that new house Jack built in Texas. The problem is when will they decide to move. From what he wrote they sure were attached to that single chamber. It took one of my houses three seasons to be used as the bats liked what they had I suppose. We are due for some warm weather here next week so I will check to see if I have any visitors then.

Frank