Yep, that's right.
It seems that "researchers suspected that the rodents were harboring poison" and a new study reveals that the rat has, in fact, enlisted the help of the "arrow poison tree" (Acokanthera schimperi) to protect itself. This tree produces a poison that was once used by hunters, who coated their arrow points with it, to take down big game, such as elephants.
This resourceful little rodent is immune to the poison's effects and, after gnawing on the bark for awhile, use their poison-laden saliva to coat their pelt. Such smart little critters. Read more at Science Magazine.