• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies living kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • raven ranson
  • Jocelyn Campbell
  • Julia Winter
stewards:
  • paul wheaton
  • Burra Maluca
  • Devaka Cooray
garden masters:
  • Anne Miller
  • Pearl Sutton
  • Joylynn Hardesty
  • Shawn Klassen-Koop
gardeners:
  • Joseph Lofthouse
  • Bill Crim
  • Mike Jay

Bats - your most effective insect control  RSS feed

 
pollinator
Posts: 422
Location: Zone 8b: SW Washington
23
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Dave Bennett wrote:
I wish I could get a reasonable count of just one slot of one of my bat houses.  Then I could make a good estimate as to the size of my "neighbors."  My bat houses are a bit larger than the standard plans available all over the "net" because I wanted more bats in the neighborhood.  There is a huge drainage "pond" at the end of the street so the mosquito population was huge when I moved here 17 years ago.  Now it is much better.



If the house is packed to the gills, you can do an exit count.  Otherwise you can take a flash photo looking up into the house and count the bats in the photo.  But you have to orient the camera in a certain way in order for that to work.  Let me know and I'll post the procedure.
 
pollinator
Posts: 928
Location: Melbourne FL, USA - Pine and Palmetto Flatland, Sandy and Acidic
36
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
An interesting design aspect I have found is what I call for my lack of better terms the "igloo effect".  Essentially, because air heated by the ground and the bats rises, there should be a steep step or slope from the ceiling of the entrance to trap the warm air.  Also the slop prevents water traveling in the cave as long as it is above the flood plane.  I did a brief drawing to show how this works.  I presume that the bats can hibernate at least in a  comfortable 70 degrees since the ground here is typically at mid 60s degrees Fahrenheit.  The earth/concrete is not a good insulator but it is a good conductor of heat from the ground.  Please do not look at this drawing for dimensions, its a show for concept.  I would prefer 12ft ceilings to 3ft ones.

 
Posts: 686
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

adunca wrote:
Actually the first bats in the US with White-nose Syndrome were in a cave in New York:


Here is a paper on bat hibernation in New York: http://www.oneonta.edu/academics/biofld/PUBS/OP/Hibernating%20Bat%20Populations%20in%20Eastern%20New%20York%20State%20OP%2014.pdf


Well actually there are caves in NY just not anywhere around where I grew up.  I did not say that there weren't any caves I said there aren't any around where I grew up.  Big difference.  I just read some of that study Schoharie, Albany, Montgomery counties is where the study was conducted.  One hundred + miles away and more towards the north from where I lived but I did notice that the map of the suspected transmission path passes through where I grew up.
 
Amedean Messan
pollinator
Posts: 928
Location: Melbourne FL, USA - Pine and Palmetto Flatland, Sandy and Acidic
36
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
No need to get feisty, you both are right.  A cave is not essential, more ideal for hibernating bats.  I imagine bats have found homes in many areas but also consider that it does not ensure their survival.  A residence such as a cave is ideal, but not the only solution.  There is a reason that bats gravitate towards caves.  You have to consider that it is at cool temperatures during the hot summers and more importantly warm in the winter months.  The geothermal energy is much to thank for this. 
 
Posts: 155
Location: Sierras
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I've used roofing tar paper (black stuff) loosely wrapped around a tree trunk (about 6' up) that's exposed to the sun - especially in winter.  They are loaded with bats... they can control their temperature by rotating around in there.
 
Dave Bennett
Posts: 686
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I was playing around with an idea for a mini "bat cave" concept today.  Nothing on paper just an imaginary vision while I consider the possibilities of providing thermal safety yet light enough in weight to allow them to be placed in areas with sources of food and water.  Multiple bat caves.  Much like purple martin "hotels" but built for bats.
 
Dave Miller
pollinator
Posts: 422
Location: Zone 8b: SW Washington
23
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I want to make sure that people understand a couple of things.

1. Bats are very selective about their roosts, especially with regard to temperature.
2. Males have different temperature requirements than females.  Females need roosts that are usually 80-90 degrees, for giving birth and raising pups.  Males prefer roosts that are a bit cooler.
3. For bats that go into torpor/hibernation in the winter, humidity is also a very important factor in selecting a hibernation site.
4. Different bat species form different sized colonies.  e.g. where I live it is better to provide a lot of smaller roosts vs. one big roost, because our bats do not form really large colonies.
5. Bats change roosts (and move around within a roost) frequently.

Here are maps showing the ranges of non-hibernating (left) and hibernating (right) bats:

(from http://www.fort.usgs.gov/wns/)

In the summer, bats that use caves/mines for summer roosts usually use the warmer parts of the cave.

In the winter, bats who hibernate use the parts of caves and mines that have cool, stable temperatures and high, stable humidity.  They will travel long distances (hundreds of miles) to reach these very special places.

So if you were to build a "bat cave" that you wanted bats to use year round (assuming your bats hibernate), you would need to design both a "summer zone" and a "winter zone".  And there is no guarantee that bats would use either.

In the wild, most bats use large caves or large hollow trees in the winter, and in the summer they use large dead trees/branches with exfoliating bark (they crawl up under the bark), or rock crevices, or warmer parts of caves.  So in the summer bats are looking for anything that is like exfoliating bark, a large tree cavity, a rock crevice, or a cave opening - which means they end up under loose siding, in louvered attic vents, under loose roofing shingles, inside chimneys, inside folded pool umbrellas, in attics, in belfries (of course!), in crevices at the bottom of bridges, under black tarpaper that people have wrapped around trees (), etc.  Oh and of course in bat houses, which simulate exfoliating bark.

So, here is what I would do:

1. Walk around your property/neighborhood just after sunset, on a night with a lot of flying insects, to see if there are any bats in the area.  If there are not, then your chances of attracting a colony are slim.  However it is still worth trying to provide at least a little bat roosting space.
2. If you have any of the roosting spots I mentioned above on your property, observe them carefully to see if they are already being used by bats.  Look for droppings below the roosting site/entrance.  They look like mouse droppings but they are very light and crumbly (they are made from insect skeletons).  There may also be some staining from body oils or urine.
Here are the droppings of Big Brown and Little Brown bats, our most common species:

(from http://bathouseforum.org/forum/small-grey-looking-bats-t764.html)
3. Most bats will not roost more than 1/2 mile from open water.  They must drink while flying, so they need open water that is at least as big as a bathtub.  If you have no open water nearby, your chances of attracting a colony are slim.  Or you could put in a pond (or stock tank filled to the brim).  They do also drink from swimming pools, although the chemicals are not too good for them.  In fact if you live in the desert, you absolutely should put in a pond or tank for bats to use.
4. So if you have seen bats and there is water nearby, your chances of attracting a colony are good.  Study up on your local bats, read everything on BCI's website about bat houses (start here: http://www.batcon.org/index.php/get-involved/install-a-bat-house.html), and put up a bat house on a building or a pole.  Make sure to follow the coloring and placement guidelines from BCI.
5. Wait a couple of years to see if bats use your bat house.  A decent sized bat house can hold several hundred bats, which if you are in town is enough to provide bug control for your whole neighborhood.
6. Now, you can start thinking about your bat cave or giant bat house or whole series of bat houses (depending on the species in your area).  I would focus on providing summer roosting space.   I would guess that even if you could provide the exact conditions your bats need for hibernation, the chances they would choose to use your cave for hibernation (vs. all the other caves, mines and hollow trees within 200 miles) are slim.   If on the other hand your bats do not go into full hibernation but just go into torpor for periods of time, then there is a very good chance they will stay in your cave all winter.  e.g. I know of a few colonies around here that stay in attics through the winter.  But generally speaking you'll need to live somewhere with mild winters in order for that to happen.
 
steward
Posts: 8019
Location: Currently in Lake Stevens, WA. Home in Spokane
302
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I'll grant that this is an older book (1925), but worthy of a read if you are interested in bats:

http://www.soilandhealth.org/03sov/0302hsted/030212campbell/campbelltoc.htm
 
steward
Posts: 2524
Location: FL
96
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
When building a batcave or a large bathouse, I think connecting a couple of baffles to the ceiling would help to reduce a cooling draft.
 
pollinator
Posts: 10180
Location: Central Texas USA Latitude 30 Zone 8
306
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Historic bat house in my locale:  http://www.batcon.org/index.php/media-and-info/bats-archives.html?task=viewArticle&magArticleID=398



There's also the Old Tunnel "bat cave"

http://www.tpwd.state.tx.us/huntwild/hunt/wma/find_a_wma/list/?id=17

I'm in "bat central" here in Central Texas, but so far have not managed to put up any bat houses. 
 
Dave Bennett
Posts: 686
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I remember seeing that tower when I was "traveling" around Texas back in the early 70's "touristing." 
 
Posts: 212
Location: Sacramento, CA
1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The house fell down? the original one because too many bats came into it. ? I wonder if you use cob you can make something like that with less cost? well place steel structure some cob and burring it? or hempcrete with a sealing on it?
 
Posts: 370
Location: Upstate SC
13
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Jordan Lowery wrote:

While many of you were watching the swarm of bats, and thinking of the millions of insects they would eat, I was trying to imagine how much bat guano must get deposited on the floor each season.  A true permaculture solution...convert too many insects into an extremely valuable natural fertilizer!



not only that, but most of these bats are eating insects outside of your property, so you get the benefits of large amounts of organic biomass coming from somewhere else. essentially bringing fertilizer to your land.

birds do the same thing but i bet bats can do it a million times better.



I get this same effect (import of nutrients) from the many hundreds of grackles and cowbirds that overnight in my bamboo groves. Their droppings fertilize the bamboo and spread out onto the adjacent land.
 
pollinator
Posts: 991
Location: Los Angeles, CA
152
books chicken food preservation forest garden hugelkultur urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Just stumbling upon this old thread -- fascinating.

The original premise is that by attracting bats, you are eliminating insects that are otherwise harmful to your garden and crops. The primary insects that bring badness to my garden are: A) sow bugs/wood louse, B) slugs, and C) those little white butterflies that lay eggs on my cabbages which turn into worms that eat them. A bat wouldn't do anything to any of the three. The sow bugs are out there in the soil, and crawl up the plant to eat their lunch. Same with the slugs. The little white butterflies don't fly at night.

We don't have mosquitos here, so even that pest isn't a pest for us. In fact, there don't seem to be too many nocturnal insects here. You'll get some moths and june bugs in the summer, but that's about it.

So while I'd love to have the free bat poop to use in the garden, their insect eating wouldn't be that big of an asset for me where I live.
 
Mike Turner
Posts: 370
Location: Upstate SC
13
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Marco Banks wrote:Just stumbling upon this old thread -- fascinating.

The original premise is that by attracting bats, you are eliminating insects that are otherwise harmful to your garden and crops. The primary insects that bring badness to my garden are: A) sow bugs/wood louse, B) slugs, and C) those little white butterflies that lay eggs on my cabbages which turn into worms that eat them. A bat wouldn't do anything to any of the three. The sow bugs are out there in the soil, and crawl up the plant to eat their lunch. Same with the slugs. The little white butterflies don't fly at night.

We don't have mosquitos here, so even that pest isn't a pest for us. In fact, there don't seem to be too many nocturnal insects here. You'll get some moths and june bugs in the summer, but that's about it.

So while I'd love to have the free bat poop to use in the garden, their insect eating wouldn't be that big of an asset for me where I live.



The easiest way to control the pests you've listed is to run free range chickens (and ducks if the slug component is significant) through your garden. There is some potential that they could do some damage to your crops but there a number of techniques you can use to minimize this. I have been running chickens and ducks in my vegetable garden for several years and the sow bug, slug, cricket, potato beetle, and other insect population are close to zero. Before that I used to have a lot of problems with small gray slugs in the cabbage and broccoli and crickets/grasshoppers were plentiful. They also seem to be fairly effective against cabbage white caterpillars since these mostly disappear from my plants once their damage to the leaves becomes visible. To control the cabbage white butterflies, I keep a butterfly net handy in the garden to use in snagging and killing any I see flying though the garden.

I've always wondered how effective bats are at controlling mosquitoes since bats do most of their hunting 10 to 50 feet above the ground in open areas, whereas mosquitoes are mostly found in and around vegetation near the ground where their warm blooded mammalian and roosting bird food sources are likely to be.
 
pollinator
Posts: 372
Location: Redwood Country, Zone 9, 60" rain/yr,
23
dog duck hugelkultur
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have a redwood stump 15 foot thick at breast height (I did not cut it!) in my back yard with a hollow in the center about 4-7ft wide, and its probably 12ft tall. I have two other taller, more slender snags (8-10ft thick) as well but I think the hollow would be my best bat habitat. Would simply attaching a sheltered box in there suffice to attract roosting bats? Do you do anything to get them there in the first place, like tie a moth to a string attached to the box?  I have some around, and they do roost in the old growth tree hollows, but more would seem better. Also, would my great pyrenees-akbash that likes to hang out in there more than his house scare them away?
 
Posts: 115
Location: Newfoundland, Canada
solar woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I don't know how many bats there are around here. But you will see them if you stand out a while on a calm night.

I was walking across the yard in daylight one day and a little brown bat flew out of the trees, hovered about three feet from me sizing me up for about ten seconds and flew off. I thought it was a neat experience.
 
Posts: 397
Location: Fairbanks, Alaska
15
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
No one has determined whether the little brown bats here in interior Alaska hibernate or migrate. I'd like to attract some; I know they've been sighted very close to our land. A friend of mine had some roosting beneath the siding of his house and I saw those, but they're pretty elusive and most people I know here have never seen one.
 
gardener
Posts: 1790
Location: Just northwest of Austin, TX
199
forest garden urban
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Not an expert here, but we have a huge bat population in my area. As far as I can tell they like to be near bodies of water. Don't know if you have any water features on your property, but if not that might be an opportunity to make your land more attractive to them.
 
Victor Johanson
Posts: 397
Location: Fairbanks, Alaska
15
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I do have springs, but no open water, however I'm planning to try a hog-sealed pond at some point. I do know they're around, though, because a lady I know had one get in her house within a mile or two away.
 
Jotham Bessey
Posts: 115
Location: Newfoundland, Canada
solar woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I was thinking about this after my last post. Besides a couple WW2 anti ship installations, there are no real caves around here. I don't think there needs to be big crevasses for them. Maybe a few mini adobe caves would work?
 
Posts: 1
Location: United States
1
books forest garden woodworking
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The bat is probably one of the most misunderstood and maligned creatures ever. The bat may never be your pet but the advantages of bats is undeniable.

One of the myths about bats is that they serve no useful purpose and are just disgusting flying rats. Think about this; in Central Texas alone, bats consume about 2 million (2,000,000) pounds of insects an hour during the summer months. The farmers are loving that and some of these farmers are putting up bat houses because of the loss of habitats for bats. These bats save the farmers millions of dollars in damage because of the voracious appetites of these bats.

Recently, I was experiencing severe insect infestations in my area, so I decided to build a bat house for the solution to my problem. As bats are the perfect nocturnal insect killer, they can devour up to a hundred insects like mosquitoes, moths, leafhoppers and other insects which are harmful to crops.

Personally, I've been using a very helpful resource for my bat house building plans. You may check it out here: http://www.merlintuttle.com/bat-house-builders-handbook
 
Posts: 1
Location: United States
hunting trees woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I'm new to the site and this is exactly why I joined. I would have never EVER stumbled across something like this. Bats? An artificial bat cave? Amazing!
 
Posts: 102
Location: Friday Harbor, WA
9
chicken food preservation hugelkultur
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I LOVE bats! They're amazing animals, and so useful for their insect control. You definitely don't need caves to have bats--any kind of natural or man-made crevice will do. We have bats living under the eaves of our house. They are most welcome, and I love watching them fly out at dusk!

Of course, bats usually carry rabies in North America and should never be handled without proper protection. But enjoy them! They're great.
 
Posts: 579
Location: In the woods, West Coast USA
29
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
For the last couple of years we've had what I think is a Townsend bat in a high window behind green shade cloth.  Surprised me!!  It's a window that faces west.   The sun was so annoying we hammered up different colors of shade cloth trying to decide whether to put an awning over it, or take the window out.  Then one day I saw what looked like frog walking across the window under the green shade cloth.  Turned out to be a bat!  It was amazing to watch.  It extended a bat wing and stretched during the day.  It cleaned itself.  It turned its head on occasion.  It waited until it was very dark before it left the window.

Then in early fall a smaller bat showed up, and the bigger bat with big ears was gone.   The smaller bat was in the window regularly all winter, except when it rained.  Then in March the big bat came back!  And started hanging out with the little bat!  The little bat moves away from the big bat, but doesn't leave.  Maybe the big bat migrated south, and when it returned in March it found its special place was occupied.  When the sun hits the west-facing window they both retreat to places where the green shade cloth is doubled over and gives them more shade.   In the past the big-eared bat has struggled on hot days to stay in the window, and sometimes leaves on a hot afternoon.  There are hawks around that are probably a threat to a bat, but they seem to be surviving.

So we installed another small window in the highest part of a shed at about 15 feet, and hammered a double piece green shade cloth over it, and a bat hangs out there during the day.

These are all solo bats, and they drop mice-sized droppings that could possibly have histoplasmosis in them.  So we stay away from the droppings.  I've cleaned off the window sills and hammered on some 45 degree roof flashing above the lower window sill that will cause the droppings to fall out or be washed out by rain.

So amazing to watch these guys!
 
pollinator
Posts: 480
Location: mountains of Tennessee
82
bee chicken homestead
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Austin bats

I watched that TX bat colony grow for 30+ years. I see bats in TN every night during warm weather. They are amazing animals. Put up a few bat houses this summer. Unoccupied so far but they say the bats usually move in during spring. Anything that eats mosquitoes is good. Trying to encourage that behavior.
 
The glass is neither half full or half empty. It is too big. But this tiny ad is just right:
DIY solar dehydrator - have you built one?
https://permies.com/t/90672/DIY-solar-dehydrator-built
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!