Preventing bats from roosting on porch

Hello,

I've completed several bat exclusions at this point, but never had one with this scenario. Just a couple bats hang out in the corners of this covered porch. It has been ongoing for years. They do no appear to be going into any nook or cranny, or even in the attic, which has multiple access points due to the strange construction of this old home, that has walls constructed totally out of concrete panels, with grooves that extend up and behind the wood fascia board. Anyway, they just hang out there sometimes, and a small amount of guano accumulates in the pathway to the front door. The homeowners are concerned about their small children getting sick from the guano if they track it through the house, which is why I received the call.

As you can see from the pictures, it is quite a large area, and the staining in the corners is apparent. If I screen off this somehow, what will keep them from roosting in the new corners I'll create? This is one case where I almost think lighting installed under the area would serve as a better solution, although I've never resorted to "deterrents".

I'd appreciate any suggestions anyone has that will not detract too badly from the appearance of the home. I considered doing some blocking off with braking and installing coil steel, painted to match the exterior, but the property owners are afraid it will look junky.

And yes the small bags in the left hand corner contain moth balls, lol... not placed there by me, of course.

Thanks for your help.

Usually these areas are night time roosts, meaning the bats may rest there for a while mid night but are never seen there during the day. They have a different spot they spend the day. Usually the bats are drawn to the security that the covered dark porch provides.

Painted metal would work, so would something clear like a plexiglass. Don't worry about creating a new corner because the fact that you are lowering that roosting point is going to be enough of a deterrent. The bats will no longer feel as secure about that spot.

If you don't need to make money on the job you could just tell the homeowner to point a box fan up for a couple of nights. Just the air flow will stop bats from roosting there. A couple nights, and they will have a new spot picked out.

Bent brown coil flashing installed neatly should take care of the problem.

Bats on the front porch video: https://youtu.be/GzTwAeIleX8

Appreciate the input fellas.

We have had good luck installing painted flashing around the upper perimeter. Taking away 3-4 inches of overhead cover is enough for bats to lose their sense of security. We glued the pieces in place with quarter sized blobs of a basic polyether sealant, but silicone may also work. Using glue improves the aesthetics and allows for removal of the pieces if needed.

Nicely done!

Was that attached with nothing but adhesives?

Correct, this was attached only with adhesive. If I remember correctly I dabbed a quarter-sized blob at each end, and then about every 2.5-feet in between. We talked through the pros/cons with the customer. First, we explained why we thought that this technique would work, but said we had not yet tried it out. So we thought using only adhesives would allow for its removal if they continued to find bat droppings (they have not seen any, which is a big deal to them based upon the constant sweeping they use to do). This is an expensive home, so both aesthetics and deflecting bats were high on their priority list.

Second, the only other practical way to secure these would be to drill screws into the mortar. This would be more intrusive, the screw heads would show, and would be more work (and more expensive). We told the customer that we were in the version 1.0 stage of this exclusion technique, and that if any of the pieces became dislodged or fell, then we would come back and fix it or find a different approach.

As a side note, the first picture shows a bat tucked in the corner. I had already excluded the opposite side and had my ladder set up next to the bat. I was in the process of retrieving the bat when it decided it would take off on its own. It dropped and flew to the opposite side of the porch and landed just beneath the metal I had just installed. It tried to climb up into that corner, reached its front thumb up to grab higher, and its arm skidded down the metal several times before it gave up and left. At that moment I became optimistically confident that this was an exclusion technique that would work.

Nice. I'm made the switch and trying to do all my exclusions with metal this year. Always looking for recommended tips on attachment options.