Visit the Team Iceshanty Proshop
Its no fun dropping a minnow in 3 inches of water in your shanty and having to chase the little bugger around.
It's the weight of the snow pushing the ice down. I drill a buncha holes not all the way through, but part way, so they become like big cups, and all the water gets captured in the holes. Did it this weekend, had two holes for fishin, and mabey 4 or 5 reservoirs to hold the flood water
I'm willing to bet this guy is on the money.Next time don't shovel the area. Try going on top of the snow.