Cut two 8-inch by 8-inch wooden squares, two 10-inch by 6-inch rectangles, one 8-inch by 6-inch rectangle and one 8 1/2-inch by 6-inch rectangle with a table saw.
Turn one of the 8-by-8-inch pieces so that the bottom corner points towards you. Measure 2 1/2 inches from the top corner and make a pencil mark. Measure 3/4 inch from this mark and mark the spot. Set a geometry compass for a 3/4-inch radius and draw a 1 1/2-inch diameter circle. Cut the circle out with a drill. Set aside.
Lay out the 8-by-8 inch back piece as a diamond and glue the 8-by-6-inch and 8 1/2-by-6-inch pieces to the lower edge so they fit snugly against one another. Let the glue dry and nail the lower walls to the back and to one another with three to five finishing nails along each join.
Glue the 10-by-6-inch pieces to the top of the back piece along each side of the slope. They should fit flush and level with the back and front edges. Secure them in place with three to five finishing nails and the join edges when the glue dries.
Glue the front 8-by-8-inch piece with the entrance cut in it to the roof and lower walls. Let the glue dry and secure with finishing nails. Glue a 6-inch dowel along the join at the apex of the roof. Sand all rough edges and surface to smooth.
Drill a small hole about an inch below the entrance and glue a 3-inch length of dowel as a perch. Paint or stain, if desired.