Context: Cameron would be waiting , and Cameron would be disappointed with her for standing here , her back against a tree , thirsting . She should go back - The smell of a girl passing brought a stop to every moral and human thought in her mind . She did n't even bother with the seduction this time , just grabbed the girl , hand over her mouth . She was n't aware of vamp - facing , was n't aware of anything until she was standing over a corpse , covered in blood , panting .

Question: What may be the reason for them not being worried about anyone seeing them feed ?
Options:
0. Because they ate before they left the house .
1. Because they are invisible .
2. Because they are going against the vampire code .
3. Because their hunger was too fierce .
Answer: 3