Feedback can be powerful, but its effects are dependent on what students do. There has been intensive research in recent years under the banner of 'feedback literacy' to understand how to help students make the most of feedback. Although there are instruments to measure feedback literacy, they largely measure perceptions and orientations rather than what learners actually do. This paper documents the development and validation of the Feedback Literacy Behaviour Scale (FLBS), which is a self-report instrument intended to measure students' feedback behaviours. A framework for feedback literacy was constructed with five factors: Seek Feedback information (SF), Make Sense of information (MS), Use Feedback information (UF), Provide Feedback information (PF), and Manage Affect (MA). An initial set of 45 questions were reviewed in an iterative process by feedback experts, resulting in 39 questions that were trialled with 350 student participants from four countries. Our final survey of 24 questions was generally supported by confirmatory factor and Rasch analyses, and has acceptable test-retest reliability. The FLBS provides a more robust way for educators and researchers to capture behavioural indicators of feedback literacy and the impact of interventions to improve it.