For quite some time I've known that we had little bats living behind one of the shutters on the window of our guest house. The clue was the persistent pile of guano on the floor. When I first discovered it I attributed it to the darned geckos, but soon realized that there was a "pile" rather than little "gifts". Some time back I had closed the shutter because of the weather & was startled when the bats flew away. I think we all have creepy visions of bats and what they can do. These are just tiny little guys who haven't bothered us or made their presence known until then. For some time I treated this as a cool thing as they eat mosquitoes so was silently cheering them on. I could only see them if I scrunched against the building and peeked behind the shutter and during the day, they weren't flying. This peaceful coexistence continued for several months, with me cleaning the guano up with increasing regularity and spreading it on my plants. I have a clothesline on that veranda and I could hear a faint humming and figured that their numbers were probably increasing. I finally decided this had to stop for sanitation reasons. I had Art pull the shutter closed so that I could get a couple of quick photos. My camera and I are both very slow, so missed a shot of the whole group, but did manage to get a shot of a few of them. It's easy to miss identifying them during the day as they're the size of a large butterfly and fly in much the same manner. Flitting instead of flying directly.
We plan on building a couple of bat houses to encourage them to stay around, but in the yard, not on the house. From what I've read, one bat can eat it's weight in mosquitoes every day and a pregnant female will eat 2 1/2 times her weight each day. Now I'd REALLY like to get rid of the geckos.