I saw stripes on a body inside a hole in a mudwasp nest (photo 2, inset top LH corner). It looked like it didn’t belong, it reminded me of a blue banded bee, not a wasp. Then the head appeared (photo 2, main body) and then ducked in again. Then its butt appeared, and some sand came falling out in response to its busy leg movements (photo 3). Back it went, right inside, and this was repeated a few times. Then it reappeared and emerged to head into the next enlarged hole (photos 4 & 5). This could be the same Sp as the bee at sighting 4664735