In the earlier snapshots, I remember skulk blocks having some tag that meant placing wool directly on them alerted nearby sensors as if the skulk patch was one organism. Unless I missed a deliberate change, this no longer applies and the tag is missing. I doubt it’s intended since this makes the ancient cities way easier and also removes a unique aspect of skulk, but it could be.

I’m pretty sure this also applied to directly placing wool against a sensor. This used to set it off, but it no longer does.