Exlor
In the end even if they didn't notice them crawling around the ship the extra oxygen consumption would have added up over time to a noticable degree. This isnt something you can simply magic away. This is would be an easy way to detect stollaways so I'm sure there would be a protocol for it in the military. Let's not even mention waste products. Space is a harsh mistress, everything is finite on a ship. Invisibility is one thing but isolating sound waves and trace particles that allow for scent to carry over is completely another. This kind of illogical heathen magic completely turns me off in science fiction. I guess I should have expected this from exlor considering past chapters.