SOLVED. Sci-Fi novel or short story. A human is kidnapped to find out why humans are so dangerous. Spoilers. [s]

[Aaron]

might be a short story instead of a book. A man is kidnapped (and maybe made immortal) by aliens so they can study him and find out how humans are so dangerous / have almost taken over the whole galaxy. He escapes by applying stomach acid to the prison bars and steals a ship. Story ends with a young telepathic alien waking up and being scared. I do not have a timeline.

Thanks,
AAron

[Sue]

"Danger-Human" by Gordon R. Dickson. https://www.baen.com/Chapters/0743471...

[Aaron]

That it is, thank you!
AAron

[Kris]

Glad you found your book, Aaron. Goodreads link - Danger—Human by Gordon R. Dickson - Sue's find.