Catherine Chalmers"s second Aperture monograph invites us to meditate on the pleasures and terrors of the common domestic pest, Periplaneta americana, also known as the American cockroach. In three different series of photographs, "Infestations," "Imposters" and "Executions," Chalmers challenges us to reconsider how we distinguish between creepy infestation and acceptable nature. With a slight B-movie quality, the images push us to think carefully about the ways in which we determine some creatures to be lovable and others best squashed under a shoe.