Chocolate is highly toxic to birds due to its content of theobromine and caffeine, which their bodies cannot metabolize effectively. Even small amounts can cause severe reactions, including vomiting, diarrhea, increased heart rate, seizures, and potentially death. Dark chocolate, with higher concentrations of these compounds, is particularly dangerous. The symptoms may take hours to appear, making it harder to treat in time. To ensure safety, birds should be kept away from any foods containing chocolate, especially during holidays when such treats are more prevalent.