Bark beetles are small insects that belong to the family Scolytidae. They typically live under the bark of trees, where they feed on the inner bark and wood. These beetles play a significant role in forest ecosystems by helping to decompose dead or dying trees, which can promote new growth. However, bark beetles can also cause significant damage to healthy trees, especially during outbreaks. They can weaken trees, making them more susceptible to diseases and other pests. Some species, like the Mountain Pine Beetle, have caused widespread tree mortality in forests across North America.