Danaus is a genus of butterflies commonly known as milkweed butterflies. They are part of the family Nymphalidae and are recognized for their striking colors and patterns. The most famous species within this genus is the Danaus plexippus, or the monarch butterfly, known for its long migratory journey across North America. These butterflies primarily feed on nectar from flowers and lay their eggs on milkweed plants, which provide food for their caterpillars. The bright coloration of Danaus butterflies serves as a warning to predators about their toxicity, a trait they acquire from the milkweed they consume during their larval stage.