Take this for what it is worth but this here is what I consider my signature style bat valve. Simple, cheap and effective. I once had a tech in training take one look at my materials and make the comment that if the customer realized the cost of materials versus the cost of the exclusion I would get shot. Try as I mught I never could get that idiot to understand that what the client was paying for was not some duct tape and plastic but what skilled hands could do with it. So without further ado here is my plastic and duct tape special.

This is the gable end entry point.



Here is the actual gap where the frieze board has seperated from the brick. Special Note; be very careful when working at the very top of a stack of brick like this. The brick is just stacked and tucked under the frieze board and portland cement must be in short supply as I don't think they add it to mortar anymore. Just pushing on the brick at this point can break the mortar joint and your left with loose brick. I've even had it break loose from the weight of the ladder alone so be very careful.



Okay, you are going to need a short length of flashing and some tapcon screws.
This is my own special twist as I was originally taught to use some sort of adhesive and liquid nails and brick makes a mess. I needed a way to stick duct tape and hit on the idea of tape and flashing. I have used a lath strip in the same way and used staples to hold my valve.



BTW, you also need a hammer drill to drill the holes.



Here is what you want when your done. I like the z-flashing as the bend holds the valve out ever so slightly.



Now start sealing the gap at the frieze board with a good grade of caulk. Be sure to get right up to the flashing.



Both sides.



Now cut you off a length of plastic 3mil or better three times wider than the flashing and long enough to hang 8-10 inches below the flashing. Using a good duct tape, gorilla or equivilant, tape the center to the flashing leaving a third to each side.



Be sure to get the plastic and tape up on the frieze board. Just as in the caulking the corners here are the weak points, if you leave a gap the bats will find it.



Now take one side and fold it up to the peak and tack in place with a staple, trim any excess. Repeat with the other side.



And here is what you end up with, an inverted cone with a double layer front. Reinforce the top of the valve with strips of tape as a gusset and staple through the tape to secure it. Space the staples and press down so as not to leave any gap at all.



A couple checks I always do. First make sure there are no obstructions inside the valve by sliding my hand up through it. I want the bats to transition out as quickly as possible.



Next I lift the valve to double check that I did not leave any gaps underneath. If this type of valve is defeated, barring inclement weather, it will be from below. Don't be surprised upon your return to have to flush some bats from this area as they will cluster under the valve for a few days.



Again, both sides. I'm very thourough on my valves as I really really hate having to things twice.



And viola the finished bat valve.



This basic valve accounts for the bulk of what I use. I just adapt it to the structure in question. If wood, omit the flashing and staple directly. As I said a lath strip can be used, they can be made as big or small as needed depending on the entry and number of bats. I did one last season that was twelve foot wide to cover multiple entries in lap siding.

Now I've shown you mine, show me yours.

Can anyone guess the species by the location?

Thanks warrior. Very nice, helpful pictorial.

Man Archive this post!

I would guess that the species that lives there could possibly be human but with some of these customers it's hard to tell.

It looks like alot of effort and material to evacuate a colony.Not meaning to be critical.A simple pet screen net hood cut to the correct size to fit the eviction point and a tube fitted in the center bottom of the net with some hercules putty and duct tape you are done in 15 mins or less if you have pre made devices.If time permits I will show what I mean.

Bob, please do so. I am always open to new ideas.

Actually it took longer to photograph than to install. Having done it so many times it goes like clockwork. As for materials I always save the short pieces and drop from other jobs plus plastic sheeting is one of those always on the truck items that serves multiple uses. No need to buy bat specific netting.

Species; they were behind the brick veneer, that's a finished wall behind the brick, and not in the soffit.

Paul the latin name for the species is superrichus bucksup. You have to be big bucks to live in a brick house. Paul you live in a brick house, right?

Okay Salys, I've never shown a picture of my house ( I would have to use Robb like you did ) so how do you know it's all brick. Ah Ha, Google Earth, that's it!

It's the one with the white van parked outside. And do you really think I could figure out Goober Earth? And I haven't talked to Robb in a long time. To quote an old Gestapo "V have our vays of knowing".

Fluorescent light tube protectors. That is the ULTIMATE place for them. Cut 4 or 5 of them about 14 to 16 inches long, flex into gap, secure with caulk. Done in less than 5 minutes. Using multiple tubes prevents back-ups, especially with large colonies. And these things flex to fit.... much easier than using PVC, and cleaner looking than old caulking tubes.

I've used "multi-barrel" tubes on some huge bat colonies, and have not had back-up problems. I almost never use netting anymore. Tubes are 100% one-way.... never a problem with crawl-unders like with netting sometimes.

This is a pic showing the clear bulb protector tube.... not the same type of gap, but you get the idea. This is one of those wonderfully designed attic vents that bats LOVE. Screened all the openings on both sides of the home and mounted tubes in the bottom holes, which is where the guano was heaviest. Small colony, so single tubes were fine.

On the gaps under rake boards like yours, the tubes can just run right down the wall. No need to angle them out, as no bat is able to crawl back up.

Great information in this post guys.

If they were across the river, I would say Mexican free-tailed bat (Tadarida brasiliensis). There would probably be a few Big Brown Bats (Eptesicus fuscus) mixed in too.

Ron your tube excluder is great. What I do with it is slit the tube to make four wings and cut a square of hardware cloth to fit the situation, then cut a hole in the center of the cloth to fit the tube. This give you a big 'ol flange to attach where ever.

Professor Fry nailed it. I have observed that the freetails have a distant preference for rock type substrates. Not to say they avoid wood because they love log homes almost as much as the big browns. It just that when I see bats behind the brick veneer it buried up in stone or concrete it's almost invariably freetails. of course where I find a colony of one it is not at all unusual to find the odd one of the other. Big browns on the other hand seem more oriented to wood structures. All of my gable vent colonies, roosted against the screen and exposed, have been big browns. This leads me to believe that freetails like the tight and dark places while the big browns are mote tolerant of light and open spaces.
Could this be due to the fact that the freetail is a cave bat over most of it's range whereas the big brown is a woodland species more adapted to standing snags and hollow trees?

Rick, maybe on your side of town it might be little browns but I ain't never seen one on the southside. I think you have to get in the ridge and valley up your way to find them

This is a flat bottom exclusion tube with pet screen added and secured with silicone as the adhesive for the screen to faciliate bat climb out assistance.I have found the screening to really speed up the bats crawl out assistance particularly on vertical drop tubes and acute angles of exiting.

These devices can be used on flat surfaces such as soffit and facia areas to name a few. The attached screen mesh hood acts as a funnel guide and sturdy attachment point to the mounting surface.It also allows unrestricted air flow to maintain the recognized and established exit point for the bats.

We typically use small balls of hercules putty for the initial attachment of the hood and along the body of the tube on all sides. Then we duct tape and/or staple the device if the surface area permits us to use those materials.If the devices are to be in position for extended periods and potential inclement weather then secure measures of attachment are a given.



Just a picture of the materials prior to construction of this device. We have hundreds of various screen hooded type devices made to attach to any number of exiting configurations. They are very light in weight and very quickly installed as many as necessary to accomadate large colonies or to address multi bat group exit points.



Here are couple of our longer hooded eviction tubes mounted in position found on a typical soffit facia squeeze point as a result of poor installation.



This is a variety collection of devices we use and I developed over the last 30 years.Always looking and finding new ideas to experiment with.Primarily the ideal function of any good bat eviction device to promote fast uninhibited exit flow and never restrict their points of exit to suit your own needs.

In other words dont try to make them go where you want because you are too lazy to mount the devices where they tell you they like to exit.This will cause structure back ups lickety split.Always mount multiple devices if needed to accomadate fast easy exiting to support the anticipated colony (s) sizes.Some places have multiple colonies living in the same structure that dont interact much with each other and prefer their own points of exit/entry.


Ron, in your photo I would have duck tapped over the other screened over vent areas to stop the air flow and light focus points. I have found this to promote faster location and draw to the selected eviction site unless that eviction site was pre determined to be the selected exit position initially.Those bats would still have been attracted to the screened areas due to the continued light exposure and established air flow.

David, we've seen many colonies as you describe behind the brick veneer. In this state we also have tons of free-tailed using concrete bridge
expansion joints, but also timber bridges (the old style) but the concrete seems to be the preferred. This winter we've had several bridges we
found them overwintering in too. It was funny to see them dead silent rather than their chatty selves we usually see during the rest of the year.

Great posts on the devices and methods folks, thanks for sharing, David, Ron and Bob!

justin

I make my tubes from empty tubes of caulking.