The European hedgehog is one of the most well-defended animals in the woodland. Whenever it senses danger, or hears a sudden noise, it erects its stiff, sharp spines, which it possesses even as a juvenile. If confronted by a predator, it curls up into a ball to protect its underside, head and limbs. The hedgehog is mainly nocturnal, and has poor eyesight, although its senses of hearing and smell are good.