If a gourd freezes before its seeds have dried it will be less likely that its seeds will germinate. The easiest way to do this is to fill a tub or sink with warm bleach water and use a wire mesh scrubbing pad to remove the loose skin from the gourd. You may then want to use a fine sandpaper to smooth up the gourd's surface. Any bug holes or blemishes can be filled with wood filler and then touched up with a matching paint to conceal the blemish. Your gourds are now ready to craft.
Gourds make an excellent home for cavity dwelling birds and are easy to make.
However, a poorly constructed birdhouse can actually do more harm than good. Some birds will build only in a nest built in a tree, shrub, etc. A hole saw attachment can be found at any hardware store or in the hardware section of a department store. Baby birds can easily drown when their home fills with rainwater and there are no holes for the water to drain. A dark color will absorb heat from the sun and the baby birds will likely die from the high temperature inside the house.