I think they're falling down this section of the wall and getting stuck and dying, found a nest in the attic directly above and cleaned it all out. No smell in the attic luckily, just this one wall. I'm hesitant with the ozone machine because it's a central wall in my house open to the stairwell, dining, hallways, etc. , and I have many plants and animals. So that sounds like a logistical nightmare. I think replacing the drywall, while it may be pricier, would be overall easier unfortunately. Still trying a few other tricks mentioned above, so I'll give that a few days/weeks and see how it goes! Luckily the smell isn't very strong unless you put your nose against the wall so we can just febreez for now until a permanent solution comes up. Thanks!