This wasp is found throughout North America. The sting is used to paralyze prey (spiders or insects) and is rarely used aggressively on humans. The female builds chambers (usually renovating old mud nests of other species) and puts a single egg and paralyzed spiders in each before sealing them. The eggs hatch, the larvae feed and pupate during winter, and emerge as adults in spring.

The adult females are adept at catching spiders to paralyze and put in the egg chambers. They are even able to land on orb webs without getting caught in the web. They can then lure the spider and capture it.

The males are up to half an inch long and the females are twice the size. The one shown here, resting on the boardwalk, is a female (judging by its size). These wasps need a supply of water for making mud, as well as spiders to put in nest chambers for the larvae.