It is frustrating when you go to all the trouble of putting up nest boxes to have them go unused. Is it the position, the way the opening faces or the contents inside? On a recent check of the rainwater tank the strainer was full of a lot of leaf material that hadn’t just washed in. It looks like a possum was furnishing its new home. In the long term it isn’t a sustainable site especially when it rains. We have moved an unused nest box onto the tank and added the leaf material and hope the possum tries out the new residence soon.