Mon 15 Apr, 2019 02:24 pm - Thanks for the quick response.
They are not hollowed out, they are actually a little bit raised. Wondering if it may be some sort of construction residue. House was built in 1983. (view)
Mon 15 Apr, 2019 01:27 pm - I pulled off some planks of wood on my kitchen ceiling and noticed some black speckled stuff. At first glance it looked like black mold, but it also could just be bug excrement.... (view)