They can sting, but they (anecdotally) sting less readily than some other species of wasps. I've been around them all my life and never have been stung. But, I've never intentionally messed with them. On the other hand, I've been stung by a couple other species that were far less patient with my presence in their general area.

mud daubers usually are as far from aggressive as yellow jackets are assholes.

I'm ngl I also been told that and believed it. I don't really feel very gullible since I've never actually been stung by one? Even destroying their nests doesn't seem to make them aggressive.

Lol my dad did the same. I never got stung tho and avoided some anxiety