These butterflies are common in tropical places all over the world. One of the most famous butterflies, the Monarch (Danaus plexippus), belongs in this subfamily. The larvae and the butterflies get poisonousglycosides from their larval host plant, the milkweed, so they become distasteful to predators. These milkweed butterflies (Monarch, Queen, Soldier) eat only milkweeds (Asclepias) as larvae. This highly effective defence strategy shields them against almost all predators. Birds soon learn to avoid these species after attempting to eat them.
Males in this subfamily have anal hairs. This body part at the end of the abdomen can be pulled back inside the body. They also have spots on the bottom wings that release scents to attract females. The male raises his abdomen and puts his hair pencils into the androconia. After the hairs have the chemical on them, the male will use them during courtship.