The spine-tailed squirrel can place its barrier of quills between itself and carnivorous hunters, such as pamthrets.
The spine-tailed squirrel, Humiscurius spinacaudatus, is a coniferous forest-dwelling sciurine squirrel from Eurasia with colors like a striped skunk.
With so many predators (both mammalian and avian) in the coniferous forests it is not surprising that the smaller mammals should have evolved such a variety of defensive ploys to ensure their survival. The spine-tailed squirrel is an excellent example of their ingenuity. It has a long, broad, flat tail with quills developed on its underside, which when at rest lie flat over the ground. However, when the animal is alarmed it throws its tail over its back and the sudden increase in skin tension erects the quills. This presents an almost impenetrable barrier and can be turned to deflect an attack from either side.