Born already running on empty
When the atlas moth breaks out of its cocoon, it has already eaten its last meal, and that meal happened weeks earlier, when it was still a caterpillar. The adult moth has no functional mouth. No digestive system. The structures that would form a feeding apparatus in other insects are either absent or vestigial, sealed shut by evolution because the adult stage of Attacus atlas simply does not need them. Every calorie the moth will ever spend as an adult was banked before metamorphosis began.
