Rat (one) out phrase
To tell an authority figure such as police, teacher, or parent of someone's wrongdoing.
I can't believe my close friend ratted me out to my parents about my truancy.
Some fuckheads must have ratted us out to the teacher about our cheating in the exam.
When he caught his friend ratting out his crime to the police, he was so disappointed.
The verb "rat" must be conjugated according to its tense.
This phrase was formed based on the meaning of the verb "rat".
If you swallow the bait, you take something that someone offers you, or agree to do something that someone asks you to do without knowing that it is a trick or way of getting something from you.
You can't just do whatever he wants you to do. Don't swallow the bait.