Per- and polyfluoroalkyl substances (PFAS) are a diverse group of human-generated molecules that consist of a non-polar fluorinated carbon chain and a polar head. Due to their beneficial properties, they are used in many personal, industrial, and military applications. However, PFAS compounds are associated with endocrine disruption, some cancers, and other negative health outcomes. Streams on military installations can have high PFAS contamination through routine activities, including using aqueous film-forming foams for fire control and regular firefighting training exercises using PFOS and PFOA. Freshwater insects developing in PFAS-contaminated streams can bioaccumulate these compounds as juveniles and transport PFAS to terrestrial consumers, including spiders, bats, and birds, after emergence as adults. We examined the potential for PFAS to move from streams to riparian predators through emerging adult insects at a military installation with a history of PFAS contamination. We found that PFAS compounds concentrate in adult insects, biomagnification factors for organisms were site and species-specific, and Tetragnatha spiders are useful bioindicators for PFAS contamination in bodies of water. Additionally, we are currently examining the role that insect nutrient stoichiometry and macromolecular composition have on the potential for PFAS bioaccumulation and biomagnification. Understanding which PFAS compounds biomagnify and what routes they move across the aquatic/terrestrial boundary can help inform mitigation efforts, as well as how PFAS compounds move through food webs.