Context: I guess the bug is biting . I went to the casino last night and spent 5 hours there . I ended up walking out with the same amount as I went in with . It was that way all night long .

Question: What do they mean by the bug is biting ?
Options:
0. They have problems with escaping reality .
1. None of the above choices .
2. They have a gambling addiction .
3. They have an alcohol addiction .
Answer: 2