About 4 years ago when we lived town I built a Mason Bee 'hive'. I purchased 20 or so pupae in the winter and placed them in the hive when it started to get warm out. Most emerged. I had a couple of photos of the adults as they came out. Every once in a while I would see one around the yard. Not sure if they were ours or not. At any rate they didn't really take to the home I built for them. Not real sure where they went. A year later we moved out of town. Discouraged be the failure of my hive I simply placed it on the ground next to the fence and forgot about it. A few weeks ago I saw a Mason Bee hanging around the barn looking for a hole. I started to think about the home I had built for them when I was in town. I figured I'd at least go get it and put it up in the sun. To my amazement these little guys had found it and had been using it probably for the past couple or three years. Unfortunately, being on the ground it was not an ideal situation. So I put it up in a better place, hopefully they will find it and continue to use it with better results. I might have to make a bigger one.