Here's why a guinea pig's ear might appear to be mostly skin:
* Young age: Baby guinea pigs have very thin and flexible cartilage in their ears, so they may feel mostly like skin.
* Breed: Some guinea pig breeds have very small, floppy ears that might not have much visible cartilage.
* Trauma: If a guinea pig has experienced an ear injury, it's possible that the cartilage was damaged, making the ear feel like it's mostly skin.
* Underlying medical condition: In rare cases, a guinea pig's ears might appear to be mostly skin due to a medical condition affecting their cartilage development or health.
If you are concerned about your guinea pig's ears, it's best to consult with a veterinarian for a proper diagnosis and treatment.