Hmmm… I wonder if a gentle mist of water would discourage them. Presumedly, they’re seeking shelter that’s dry, and getting wet won’t harm them but might annoy them enough to leave. Maybe something like a mist nozzle.
There are ultrasonic bat repellers, but I’ve no experience with them. In any case, I’d avoid inhaling while walking under or near them.
Thank you @bogman, thank you all.
The one in the picture has moved on, at least during the day. I have thought about the ultrasonic device. I’ll have to look into it.
Surely the OP came here looking for recipes, right?
Maybe this one;
That’s a good idea, Miss belle.
In southern AZ it’s definitely not good to put a bat house where it’ll get sun, because they’d be roasted in short order. Our bats nest under bridges, in caves, and in palm tree beards, mostly.
Lots of guano on the front steps when pet control stopped by. They let know they don’t do bats, but that they heard my place is notorious, and the typex( not brand) of "sound frequency " pest deterrent I bought is highly recommended.
I swept up the guano and added it to my compost, and am setting up the deterrent…which needs 6 C batteries, or the included ac adapter. Who has C batteries???
No one. We have something like these:
Nice!
Does this work? I’m surprised to see that as a realistic option. Having spent that much money on a deterrent, I’d be inclined to go to Batteries Plus or Lowe’s or Home Depot or someplace and get the real thing. I don’t have a hard time finding C cells at all. Double and triple As are much more common, though.
Thank you! I’m sure I can find C batteries everywhere around here but I realized that I stockpile A, AA, AAA, and even some of those transitor ones, and I realized I never buy C’s and D’s anymore.
I used it last night plugged in with extension cord, and I see no droppings this morning. Fingers crossed.
The funnest part is the cougar sounds, if you are using it for certain animals.
ETA Just read that D cells last longer than A’s in an adapter because they have over 4 times the capacity of a single AA alkaline. I’m assuming C’s will last longer too.
Yep, we’ve used them in our shower radio for as long as we’ve had it, probably 10 years. It’s not that C cells are hard to find, it’s that 99% of our battery-operated stuff takes AA or AAA, and we have chargers for those. But @shrinkrap is right - the smaller batteries don’t hold a charge as long.
3 days with little if any evidence of our guests, but this fellow was here today, and during the day, right above the deterrent.
You might be able to see the plexiglass we put up as a deterrent several years ago.
At least you won’t have mosquitos.
Wondering why all his friends have forsaken him. 
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Husband continues in his battle with the bat(s?) above our front door. I got this from our local Master Gardener coordinator.
Wow! Since the OP we *caught bats in our HVAC.
Came today to share this about guano as fertilizer in New York…
Awful.
Yikes! Really, any kind of fecal excrement is bound to be risky, especially if not heat-treated. Dry, dusty manures allow coliforms and other nasties to become airborne. Compost, wet and mask-up if you use manures. Here, a real N-95 or good fitting respirator is safer than nothing or a kn-95.
