Responses
Except that people who let kids die like that are already monsters inside. They've lost humanity. And if this is about not wanting to become monsters, then keeping one's humanity matters. Also, we don't know yet if monsters hurt kids. Do we? (I may have missed something.) What if they don't bother kids or what if kids are immune?
Also, dramatically, do we really want him to stay in the room until he's too weak from starvation to do anything once he ventures out? He needs to explore now, while he still has energy. :D

Don't save the kids. They're weak, will get in the way and most likely get you killed. Is it really worth your life to save them? I'm talking about survival wise here. Just saying.