Eren's idea of kaiju biology is sketchy. More detailed than someone without a vested interest in the topic, maybe, but no more than is widely available in the media. He doesn't know all that much, and he's suddenly very aware of the gap between his knowledge and hers. Instead of looking embarrassed, his kneejerk reaction is to try to close it.

"They're already dead, aren't they? The specimens, that is." So he presses, and it earns him a few stifled groans from the trainees behind him as he prolongs (what was supposed to be) a brief introductory lecture.