no it does not use spikes to protect itself
Hedgehogs have spines to protect themselves from predators and threats, when threatened they curl into a ball with their spines sticking out.
The pointy things on a cactus are called spines.
its a protection which animal have to protect itself from the predator...
to protect itself from creatures that could harm it.
Porcupines have quills.
So that the sea urchin can protect itself from is enemies, it also has venomous spines. They also use their spines to kill other sea ceatures, so they can eat them.
Echidnas are known for their spiky spines which protect them from would-be predators. Echidnas have strong front legs and sharp claws that enable them to dig quickly into the ground to avoid danger. They "flatten out" as they dig, appearing to sink horizontally into the ground, thus ensuring their sharp spines are exposed through the process.
So that the sea urchin can protect itself from is enemies, it also has venomous spines. They also use their spines to kill other sea ceatures, so they can eat them.
they have the spines to protect them from your face
A bubblefish is otherwise known as a puffer fish. It is a small fish covered in external spines that will puff itself up into a sphere to deter predators. The spines are also poisonous.
Porcupines have sharp spines on their back which will harm predators if they touch them. Porcupines also can blend in with its natural surroundings.
Most cacti's natural defenses are simply numerous sharp spines all over it, however some have poisonous/acidic sap inside it which it can fill its spines with or even (in a few cases) regurgitate it upon its attackers.