Although location-based augmented reality helps students explore and learn, they spend the vast majority of the activity interacting with the screen, to the detriment of direct interaction with nature. This interferes with the pedagogical objective of immersion in nature, which would foster the formation of environmental affects, an essential mediator for transforming knowledge into pro-environmental behaviors. As people interact with screens more and more, concerns have risen and so have interventions to mitigate excessive screen use. Using a nudge can positively influence the way the tablet is interacted with. The goal of this experimental study is to observe how framing the activity can impact screen interaction behavior. We gave participants different verbal instructions before a learning activity on biodiversity with location-based augmented reality. Their gaze was recorded using mobile eye tracking glasses to measure screen time. We found that a nudge reduced screen time, suggesting that the strategy is effective in influencing short-term behavior. The control group, however, reported better usability. We found no evidence of an impact on the other indicators. These results have theoretical implications for optimizing the role of technology in mobile learning, as well as practical ones on how to design nudge-based scenarios.