Bats and Cluster Flies

[AncientHouse]

Hi there,

We bought a 140 year old fieldstone house and did a complete interior renovation. We are on well and septic. The question I have is...there are 2 parts to our house, the brick addition was done in the 80's and the stone part that we renovated. The stone house doesn't have soffit. It has beautiful wood and molding with an air gap. Problem is that the air gap between the wood and the stone is letting in the bats along with major amounts of cluster flies in the fall. [img]/forums/images/icons/frown.gif[/img] We are thinking of cutting 2 holes on the under part of the wood on either side for vents so that we don't have to remove the wood for soffit and then we'll seal the air gap. We're having a hard time getting rid of the bats. The peaks are quite high and we tried to put screen on any apparent entry holes with a bottom exit but they are still getting in. [img]/forums/images/icons/mad.gif[/img] And if they can get in... then the more annoying cluster flies will easily get in. This is our 1st country home but we love it. Any ideas so that we can live alone in this house without our little friends?

[Pat]

Ancient, Isn't there a way to encourage the bats without keeping the flies. I am not familiar with cluster flies but you sound like they are a BAD THING. In general, bats are a good thing and are not the villians they are often thought to be.

If it were me I would be building bat houses and putting them out prior to sealing the bat entry points of the house to encourage the bats to stay nearby. I'd consider installing the bat houses under the eaves or near their current entry points. Bats have to eat an awful lot of insects to stay alive and many of those insects arre mosquitos. If you have many bats and get rid of them there will be an immediate increase in your insect population. Given the concerns regarding West Nile Fever and other mosquito carried disease, I'd think you would be seriously concerned about maintaining and attracting bats to your locale.

On a related issue: be advised that purple martins eating huge quantities of mosquitos is a myth, perpetuated by the ignorant and those selling purple martin houses. University research has failed to observe purple martins feeding on mosquitos. It seems that one of the purple martin's favorite foods is dragon flies. Ironically dragon flies do eat a lot of mosquitos. The end result of having purple martins colonies in an area is increased mosquito populations since they don't eat the mosquitos but do eat the dragon flies who do, or would if not eaten by martins.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[Handyman]

I'm not sure of the structures design.. but can you use some type of Alum sreening to block the holes ?

[AncientHouse]

Hi Pat,

I didn't mean to make anyone think I had anything against the bats. We do have bat houses up on 2 sides of the house. But what is happening is they somehow get into the house and run into problems. We had one end up in the intake duct and followed it to the furnace and became stuck in the filter and died. We didn't know what the smell was until we went to change our furnace filter and there was a wing sticking out. We found a hole in the intake that was left open by the duct cleaning people in error so we've sealed it. But how did this little bat get into the basement. Cluster flies are flies that look for buildings for the winter and then they cluster together by the windows inside by the hundreds. They are quite the problem as they are only by the window at night. During the day they are all over the house. So I figure if the bats can get in then the flies surely can. There are different ways to get rid of the flies but I wouldn't want to do it while the bats are in the house. I heard about some companies that have a sonar gadget to lure the bats out. Anyone heard about that?It's very difficult to know when they are all out in the dark. I have to figure this out this month as the cluster flies start entering buildings in August.
Thanks. [img]/forums/images/icons/smile.gif[/img]

[AncientHouse]

Hi Handyman,

Our house is fieldstone. We've attached some screen to the wood where the stone meets on top but left the bottom side open so the bats can get out but they aren't suppose to be able to get back in. Maybe we haven't found all the entries. We're not great with high places. Any other way to get to the top of the house without standing on the roof or on a latter? Maybe a cherry picker?

Thanks. [img]/forums/images/icons/smile.gif[/img]

[Pat]

Ancient, Too bad the bats don't eat the flies. Do you know if there is a time of night when most or all the bats would be out of the house so you could close up your pre-staged entry plugs? You might trap a few but probably not many. NOt sure how an ultrasonic signal would draw thte bats out of their quarters. Maybe it simulates the ecolocation sounds of a furious feeding frenzy to attract the attention of hungry bats. The echo location signals are species specific and just being in the frequency band of interest is not likely to attract bats. It is like expecting a noise within your hearing range to cause you to do something specific.

Perhaps a strong ultrasonic signal in the spaces where the bats are "hanging out" would drive them away. There are ultrasonic pest control devices that work pretty well on various critters so I suppose they could work on bats. I used a couple different kinds to keep dogs and cats from leaving "love notes" among the plantings and landscaping. Very effective, especially on a psuedo random repeating mode with a warbling ultrasonic signal.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[AncientHouse]

Hi Pat,

It is too bad that they don't also eat the flies. They are so quick going in and out it's hard to work in the dark on ladders. That's why we were thinking of some type of cherry picker crane rental but I'll have to check on pricing for that.
Thanks for all your help.

Lee [img]/forums/images/icons/smile.gif[/img]

[cowboyjg]

One of my employment adventures involved a 7yr stint in the pest control industry. Dealing with critter invasions was one of my areas.

First, a few pics (if possible) would be helpful. You should have been able to identify the specific entry points for the bats from the rubbings/droppings on the stone or wood where they come and go. It is not likely that they utilize every bit of the opening that allows airflow into your attic space.

How you fashion your wire mesh is critical. That will be dictated by the surfaces you have to work with and how they are situated. Part of what I am getting at here is that you should be able to screen (using both wire mesh on the outside and fiberglass window screen underneath) in the opening to a point so as to limit the entry of the bats and the flies to a specific area. Once the bats have left you can then screen in the exit points so as to now address the flies.

Of course, if you're going to spend money on a cherry picker, you might consider a call to a local professional. The costs may be comparable and with the professional you should get some sort of warranty.

You will also have the issue of the Bat Guano to have to contend with..... .[img]/forums/images/icons/smirk.gif[/img]

Sure hope this helps.

[AncientHouse]

Hi,

I had a feeling that a cherry picker would be expensive. Looks like we are back to ladders. I'll have to get some pictures. We put mesh where we saw holes with guano. We sealed 3 sides of the mesh and left the bottom unsealed so they could get out. When we look into the attic from the inside, it looks clean. But where the peak at the front of the house is, there is a stone wall separating that part of the attic and it has a square cut out approx. 1ft x 1ft. We were thinking of putting mesh there but aren't sure how to seal it to a stone wall. On the other side of the wall is the part of the attic that is the front peak of the house which is where the bats seem to be hanging out. We can hear them from the inside of our bedroom. We can't access that side of the attic from the inside. I have a feeling we might have missed some entry points on the side of the house. We're having a heat wave in Ontario which isn't helping for outdoor work. I'll try to get pictures. We have bat houses on 2 sides of the house but they still want our house [img]/forums/images/icons/crazy.gif[/img] . I guess we're lucky it's not mice. [img]/forums/images/icons/smile.gif[/img] But it's the flies that drive us crazy [img]/forums/images/icons/crazy.gif[/img] In August as it starts getting cooler they start coming in and stay all winter in the hundreds. I definitely can't deal with the flies again [img]/forums/images/icons/mad.gif[/img] So if I can't get the bats out soon...I'm still going to have to put out the spray for the flies. [img]/forums/images/icons/frown.gif[/img]

[cowboyjg]

A canadian heat wave......I'll trade you... [img]/forums/images/icons/grin.gif[/img]

Attaching the mesh to the stone is pretty simple. A cordless or corded drill, Four 1/4" x 1 1/2" tapcon or other masonry screw and the appropriate size bit. Cut the mesh a few inches wider at the bottom than the top and put a little fold in the center from top to bottom so as to create a small channel for them to get out. Drill the morter joints for the screws not the stone itself. Screw the mesh to the stone wall. You may need to use a washer with the screw.

As far as missing entry points, they will become evident as you close off the ones you find.