Do butterfly houses really work?

Butterfly houses are more of a garden decoration than a way to attract butterflies to your yard. Although a few butterfly species seek shelter for winter hibernation or a shady roost during the hot summer, most butterflies usually rest on vegetation or in trees. However, if you put your houses in a protected area near woodlands, you could attract a mourning cloak or question mark to them. And in areas where Milbert's tortoiseshells are found, a butterfly house might be effective, since these butterflies hibernate in large groups. Be aware that butterfly houses also make good homes for wasps and hornets.