A pygmy nuthatch

We have several of these pygmy nuthatches around our building. Normally I see them banging away on a tree to build their nests. However, our little guys have decided that our building is better. Our building has a stucco exterior. So they are pounding their way through stucco, metal mesh, Styrofoam and attempting to get through the sheathing. If they ever make it through the sheathing, there isn't much left except some insulation and drywall. Fortunately that haven't succeeded making it all the way through the sheathing...but they have been close. We get the building patched and they keep going. They must have really tough beaks and skulls.

Unfortunately my office mate and I, they have chosen our side of the building to bang away at. Off and on all day long you hear this incessant banging......tap tap tap ratatap tap ratatap tap ratatap tap tap tap ratatap tap. Sigh......