3. 4. Size: Approximately 3-4 inches. Care: Easy 6. 7. Lifestyle: Nocturnal, active at night. Scientific Name: Manduca quinquemaculata 2. 5. Handling: Hornworms are handable but may try to hit you with their heads in defensive and may even try to bite. Lifespan: Approximately 4-5 weeks. Community: Yes, as long as you have lots of room for them to move around. https://thegardendiaries.blog/2020/07/05/dont-kill-that-tomato-hormworm 1.