Here's why:
* Density: Porcupines are heavier than water, meaning their body density is greater. This makes them sink.
* Quills: While their quills might seem like they could help them float, they are actually quite dense and don't provide enough buoyancy.
* Lack of Adaptations: Porcupines are not aquatic animals and lack any special adaptations for swimming or floating.
If a porcupine falls into water, it will likely sink and drown unless it can manage to get to a safe shore or find something to cling to.