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10 animals that are bad for the environment

By: Bryan Nelson on April 14, 2010, 1:05 p.m.
Bark beetle damage in trees

Photo: vsmoothe/Flickr

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Bark beetles

Many species of bark beetle choose dead or rotting wood to reproduce in, but several species (including the mountain pine beetle of western North America) are known to attack and kill live trees. Whole stands of forest can be destroyed if bark beetle numbers get out of control. The bugs can also be carriers of disease, as is the case with the American elm bark beetle which transmits Dutch elm disease.