Bats play critical roles in ecosystems globally. However, key aspects of bat biology, from the causes and consequences of population declines to their ability to transmit viruses to people, remain poorly understood. This AccelNet project establishes the Global Union of Bat Diversity Networks (GBatNet) to fill key knowledge gaps and create an international structure to accelerate discoveries across disciplines and borders. The network of networks fosters new avenues for global research exchange through coordination of joint research, education, and outreach. GBatNet links 14 regional and global networks with a shared vision to address pressing questions in bat biology of direct relevance to ecosystem and human health. GBatNet will advance understanding of mechanisms that govern the ecology and evolution of bats, and address NSF’s Big Idea Understanding the Rules of Life. The network of network forges novel connections among experts in paleontology, evolution, morphology, ecology, virology, genomics, and conservation. GBatNet will address 3 broad questions : (1) eco-evolutionary dynamics – what are the feedbacks between ecological function, evolutionary adaptation, and rapidly changing environments?, (2) metabolic homeostasis – how do individuals maintain metabolic homeostasis, and what are the evolutionary contributions and ecological consequences for populations and species?, and (3) tree of sex – what are the evolutionary and ecological consequences of genomic rearra