Based on the story "The Rat Trap," the peddler, also known as the tramp, had to take shelter for the night because:

• It was getting dark: As night approached, it would have become increasingly difficult and dangerous to continue wandering around in the countryside.
• He needed a place to rest: The peddler was tired from walking and needed a place to sleep and recover. He was a vagrant with no fixed home and relied on the generosity of strangers or any available shelter he could find.

For more context, you can read a summary and analysis of the story "The Rat Trap" at Vedantu, Learn CBSE.