The man has been in a rat race all his life. No wonder he is enjoying his retired life to the fullest.
smell a rat觉得哪里不对，起疑心
When he made that offer, I smelt a rat. It sounded too good to be true.
play cat and mouse with欲擒故纵，玩弄，忽冷忽热
If you keep playing cat and mouse with your boyfriend, he will get another girl.
First, my husband became a coach potato, and now my son is becoming a mouse potato.
quiet as a mouse鸦雀无声，悄无声息
We remained as quiet as mice to avoid being detected by the guards.