Interest is growing among out-of-school time (OST) educators in integrating the arts into STEM (science, technology, engineering, and mathematics) programming (e.g., Kelton & Saraniero, 2018). Arts-integrated STEM--or STEAM--programming now takes place in a wide variety of OST environments, from relatively institutional learning settings, such as a library, to emergent or fluid settings, such as a pop-up program in a housing development community room. Educators often consider OST environments to be conducive to creative and conceptually ambitious STEAM programming because these spaces have the potential to deconstruct rigid boundaries between disciplines that formal education often reinforces. In this article, the authors discuss an OST STEAM program titled Zoom! that they designed and implemented in a summer camp in July 2019. Zoom! used visual arts strategies to support elementary-aged children in thinking about and communicating systems-level ideas related to the human microbiome--the community of single-celled organisms that live on and inside the human body.