We didn't realise we had a possum in this skinny tree hollow - we think it was outside in the day because the hollow faces to the sky and we had heaps of rain (hence it is wet inside). The hollow is about 2.5m above the ground but the possum is at least 1m down inside the tree. My daughter insisted on putting carrot out for him/her. We could see underside of skinny tail clearly when he/she went back into the hollow (which looks way to small for it!)