Red-billed oxpeckers (Buphagus erythrorhynchus) enjoy the company of furry friends. It's a bit of a complicated relationship, though. While on the one hand they might help big mammals keep ticks under control by eating them, they have other motives for hitching a ride. Harmlessly enough, they like to pinch freshly plucked hair to line their nests, and enjoy the occasional ear wax snack. But at their most sinister, they will actively keep wounds from healing so that they can feed on the blood. Vampire birds!
behaviour and evolution