Hi, Shelley,
I am definitely not an expert, since I've only had two gerbils ever, but
I think it must just be a personality thing, or maybe physiology, like one
had more control over his body than the other. Any time we had our gerbils
out, Mario would always leave little "presents", and Luigi never did. After
we became aware that Mario was probably the dominant one, we thought it might
be a dominance thing. But even after Mario died, Luigi almost never left us
little "gifts", and when he did it was toward the end, when his tumor was
getting worse, so he might not have had as much control as he had when he was
in better health. Take comfort in the fact that gerbils are relatively easy
to clean up after!
Bye for now,
Mo
