Are koalas aggressive?

Koalas are not aggressive by nature, and they usually avoid humans and other potential threats. There are exceptions, however, such as when a koala is startled or is approached during the mating season or when it is injured or distressed. In these instances, a koala may hiss, snarl, or grunt as a warning or even bite or lash out with its claws, which can inflict significant harm when used as a means of defense.

Koalas are characteristically calm animals, owing in part to a low-energy lifestyle fueled by a nutrient-poor eucalyptus diet. As a result, they tend to conserve energy by engaging in extended periods of rest and inactivity and generally prefer to avoid confrontation. When threatened, they often retreat to the safety of the trees. To avoid causing koalas distress, humans can respect their space and observe them from a distance.