In a study by the ethologist H. B. Davis in 1908, raccoons were able to open 11 of 13 complex locks in fewer than 10 tries and had no problems repeating the action when the locks were rearranged or turned upside down.
U istraživanju etologa H. B. Davisa iz 1908. godine, rakuni su uspjeli otvoriti 11 od 13 kompleksnih brava u manje od 10 pokušaja i nisu imali problema u ponavljanju akcije kada su brave bile promijenjene ili okrenute naopačke.