When using a GoPro to capture unusually close footage of grizzly bears for the Great Bear Stakeout for BBC, I had a young bear actually chew on the camera. Amazingly there was no damage to the camera! Some of this clip appears in the film Great Bear Stakeoout on BBC and Discovery Channel. Video copyright Brad Josephs.
Video by: http://www.alaskabearsandwolves.com/making-of-the-great-bear-stakeout-behind-the-scenes/