Conservationists need to measure human behaviour to guide decisions and evaluate their impact. However, activities can be misreported and reporting accuracy might change following conservation interventions, making it hard to verify any apparent changes. Techniques for asking sensitive questions are increasingly integrated into survey designs to improve data quality but some can be costly or hard for non‐experts to implement. We demonstrate a straightforward, low‐cost approach, the “bean method” in which respondents give anonymous answers by adding a coloured bean to a jar to denote a yes or no response. We apply the bean method to measure wildmeat hunting and trading over two years at a conservation project site in Gola Forest, Liberia, and extend the technique to accommodate questions about hunting frequency. We compare responses given using the bean method and direct questions, for groups that did and did not participate in conservation interventions. Results from the bean method corresponded to those from direct reports, giving no indication of change in question sensitivity following conservation interventions. Estimates from both methods indicate that wildmeat trading decreased in project and non‐project households (from 36% to 20%), while hunting decreased in one project group (38% to 28%). Where inconsistent answers were given (2 to 6% of respondents), differences were in both directions and were most likely attributable to measurement error. The bean method was quick and straightforward to administer in a low‐literacy setting. We show it can be modified for answers of more than two categories and consider it a valuable tool that could be adapted for a wide range of conservation settings.