where are you seeing them? On plants? If so, which one(s)? Or where?

Southern California, not near any vegetation, just crawling as fast as it could across hot asphalt. The kids are saying they see a lot of them around the school. Not sure exactly sure where they are seeing them, as for vegetation. I'll ask on the nature forum.

Mourning cloak?

Nonmember is probably right. The mourning cloak lays eggs in clusters so when they hatch, you see them in groups. It's the right time of year.

Oh yes, that's it! Thank you.