Digging, of course

Today we finally had some warmer weather, the sun was shining and the snow piles are melting like butter in a hot pan. The boys headed outside for some fun snow play. I envisioned snowball throwing, but no. As I look out the window, I see them huddled together digging a hole. Sand, or snow, it does not matter, the perspective hole is calling these two boys. The mining and geology genes????