Black & Yellow Mud Dauber

Sceliphron caementarium is one of the most common and broadly distributed solitary wasps in the world, found across North America, Asia, and many other regions through accidental introduction. The species is famous for her mud nest construction. Females collect mud from puddle margins, roll it into pellets, and build cylindrical 'organ pipe' chambers on vertical surfaces — house siding, barn beams, attics, garages, even cliff faces. Each completed nest contains 10-20 cells. Each cell is provisioned with 6-15 paralyzed spiders (the female stings them, drags them back, packs them in), then receives a single egg before being sealed. The larva consumes the live paralyzed spiders, pupates, and emerges as an adult the following summer. Mud daubers are particularly fond of black widow spiders and jumping spiders — the species is one of the most effective natural controls on spider populations in much of its range. Old, abandoned mud-dauber nests are quickly colonized by other solitary wasps and bees. Mud daubers are non-aggressive toward humans; stings are vanishingly rare and require physical handling.