00:00

Question 8·Medium·Central Ideas and Details

Urban ecologists studying the feeding habits of city-dwelling raccoons placed motion-activated cameras near garbage bins in several neighborhoods. The cameras recorded whether a raccoon inspected a bin, attempted to open it, or succeeded in extracting food. After reviewing three weeks of footage, the researchers found that raccoons that had previously succeeded at one bin were far more likely to attempt to open similar bins in the future, whereas raccoons that had never succeeded tended to ignore the bins altogether.

According to the passage, what evidence did the researchers use to decide whether a raccoon had attempted to open a garbage bin?