Bears may self-medicate against ticks by rubbing against trees

Brown bears often scratch their backs on trees, leaving chemical signals to other bears.Now it seems that the act also helps protect against ticks

To Jake Buehler

Bears that turn their backs to tree trunks and scratch their backs may smear themselves with irritating resins, keeping blood-sucking parasites at bay.

brown bear (Ursus Arctos) periodically rub your neck, chest and back against the tree. This behavior is often thought of as chemical communication with other bears, by the animals attaching their own scent or picking up a coating of aromatic resin. Bears are also drawn to smellier options for scraping wood, such as creosote-treated utility poles.

However, many aromatic vegetable oils and other substances have antifungal properties, so…