 Three remarks about this definition are in order. First, it does not rule out the possibility that at least some things made by non-human animals are artifacts. Spider webs do have a purpose, for instance, and are clearly made rather than naturally occurring. But we may hesitate to attribute intention to the spiders, given the instinctive nature of their web-weaving behavior. Beavers, on the other hand, might be thought to intentionally construct dams in order to create ponds. This implication of the standard definition fits well with the burgeoning evidence for sophisticated cognition among non-human animals in general, and their ability to manufacture and use tools and other structures in particular (Shumaker, Walkup, &amp; Beck 2011; Gould &amp; Gould 2007). This is an important area of research in ethology and comparative psychology. However, for the purposes of this article we will focus on human artifacts.