Judging from his size, I strongly suspect that this is the same possum which was in our compost pile a couple of weeks ago.  Since I have not seen him in my compost pile in the meantime, it seems that he has been eating somewhere else.  He ran in front of me, then cut over to the other side of the fence.  Maybe he hid behind the Amaryllis under the Sago palm.   He really scampers pretty fast.