Which feature of a porcupine suggests that it is prey for larger animals?

The fact that porcupines have quills suggests that they are prey for larger animals. Here's why:

* Defense Mechanism: Quills are a primary defense mechanism for porcupines. They are sharp and barbed, and can inflict painful injuries to predators. This means that predators need to be wary of porcupines, and that porcupines are not easy prey.

* Vulnerability: While quills are effective against most predators, some animals are large and powerful enough to overcome them. For example, bears, wolves, and large cats have the size and strength to ignore the quills and kill a porcupine.

* Evolutionary Pressure: The fact that porcupines have evolved such a strong defense mechanism implies that they have faced significant pressure from predators throughout their history.

Therefore, the very existence of quills, while a powerful defense, also indicates that porcupines are vulnerable to certain predators and have evolved a defense specifically against them.