Given a scientific passage and an answer, generate a question for the given answer.

Passage: An insect's abdomen contains most of the internal organs. Like other arthropods, insects have a complete digestive system. They also have an open circulatory system and central nervous system. Like other terrestrial arthropods, they have trachea for breathing air and Malphigian tubules for excretion. Answer: the abdomen
Where are more of an insect's internal organs kept?