Skinnypigs are really particular about their environement, it even comes down to such silly things as scents, would you believe that more so than any other breed, they're more sensitive to hormones due to their chromosonal differences to the usual breeds, so if they're handled by a teenager they tend to show more discomfort, given the pheromones that're released, it's called the off-gassing effect, I'm sure you already know this, and will have taken the necessary steps to avoid this issue, but it's worth noting.