Most birds that can be attracted to feeders are insect or seed eaters. Insect_eating species, such as chickadees and woodpeckers, are attracted by animal fats or "suet." This can be obtained from the grocery store or trimmed from beef, pork, moose, caribou, or other wild meat. Fats that have a low water content are best in areas with severe cold, because they freeze at lower temperatures. Peanut butter, another fat, also attracts birds to feeders. Its sticky consistency occasionally causes problems for birds, so it should be mixed with melted animal fat and cornmeal or rolled oats. That expensive peanut butter will last longer if it is mixed with other ingredients, anyway.
Use the proper materials. Wood is the best material for birdhouses. Other materials (like metal or plastic) may not insulate the nest enough, so eggs or young could become chilled in cold weather or overheated in warm, sunny weather. Use rough_cut wood slabs, tree sections, or 3ǚ_inch plywood. Never use creosote_treated wood as creosote may kill the eggs or chicks.