Care: Easy 6. Lifestyle: Nocturnal, active at night. Handling: Hornworms are handable but may try to hit you with their heads in defensive and may even try to bite. Community: Yes, as long as you have lots of room for them to move around. Scientific Name: Manduca quinquemaculata 2. Lifespan: Approximately 4-5 weeks. https://thegardendiaries.blog/2020/07/05/dont-kill-that-tomato-hormworm 4. Size: Approximately 3-4 inches. 5. 3.