Butterflies and moths are similar animals, but they have some general differences. The main difference is that butterflies have knobs, or clubs, on the tips of their antennae. Moths may have threadlike, feathery, or blunt antennae, but their antennae lack clubs. In addition, most moths tend to fly chiefly at night, while butterflies are active during the day. When at rest, most moths hold their wings folded flat over their backs, while butterflies hold their wings upright over their backs or bask with them spread flat out to the side. Many species of moths have dull gray or brown wings, and butterflies often have wings with colorful patterns.