Answer:
The theme of the fable would be:
Always remain humble and live within your means.
This could be seen in the action done by the city mouse where he was boasting that he is living in riches rather than penury. He also never told his friend, country mouse that, the house was never his, thereby creating larger than life living lifestyle.
The best summary to support the theme is the statement made by the country mouse "I'm off. You live in the lap of luxury, I can see, but you are surrounded by dangers; whereas at home I can enjoy my simple dinner of roots and corn in peace."
Step-by-step explanation: