Whats the name of this VERY OLD horror movie?

It had a scene in it where a bunch of young women and men were stranded and a dude in a pick up truck stopped and picked them up. A bunch got in the back of the truck and a couple set up front with the driver. While driving along, the dude driving asks the pengers if they would like a snack and then he reaches in the glove compartment or something and pulls out a living white mouse and pops it in his mouth. Blood sort of spills out of his mouth as he munches away. It was showing in the 70's. Any idea's?