Updating Robots.txt and Sitemap.sml files

This might seem like a stupid question, but do I need to update my website’s Robots.txt and/or Sitemap.sml whenever I add pages to my site? Thanks.

When you add new pages to your website, you must obviously update your sitemap and updating robots.txt depends on whether you want search engine spiders to crawl those new pages or not.

Thankyou