I think we can all agree that animals are adorable. They are highly intelligent, however they are still animals. Hunting, being predators and live in the wild will always be parts of their true nature.
One more interesting aspect about them is their invasion tendency, sometimes they migrate to other territories because of the lack of food, as a result of climate change or their habitat went extinct.
And when they do so the result can be almost catastrophic.
They can be aggressive to humans and be a threat to the local ecosystems and ecology. Here are a few cases where some creatures migrated and caused a true chaos.