A butterfly house is a dark, safe area in your garden where butterflies can go to rest, away from predators. Make sure that you include a shallow dish of water nearby so the butterflies can stay hydrated. Ideally, plant a variety of plants around the butterfly house to attract butterflies to it. You can also add butterfly-friendly plants, such as buddleja, which scents the air with a beautiful fragrance, or wild marjoram. Make sure that your butterfly house contains a piece of bark or a branch for them to land on once they fly inside it, and make a sugar solution to attract them.