Excavator: Ground. All known panurgines are ground nesters (Rozen 1967). C. baldocki was observed nesting in bare saline soils at Pêra (Portugal). At both Cacela Velha and Pêra, male bees were seen investigating possible nest holes, running quickly between entrances and flying low over the ground. Nesting was only observed within a short distance from the coast, and only on soils which had a clear saline influence.