There are some ways in which a caterpillar's life is very convenient. After all, from the very moment it hatches from the egg, the caterpillar is sitting directly on the food source it will need for the next 7 - 10 days. All the caterpillar has to do is eat and grow, eat and grow, as this fellow has clearly been doing.
Caterpillars face plenty of other challenges, so it's nice that at least their food source is always provided. All caterpillars are specialists, and butterflies lay eggs appropriately. Monarchs will only lay eggs on milkweed, as this is the only food their caterpillars will eat. And My Florida Backyard is happy to provide as much milkweed as these wonderful little creatures can use!