I've started receiving requests for paths such as
several times a day from the Bingbot. This started a couple of days ago.
Anybody know why this is?
I've seen this type of behaviour from both Googlebot and Bingbot before. It is almost never caused by a bug in the crawler itself. It is usually caused by a bug in a website that they crawl that has links to your site or text URLs in the page that look like that.
When it happens, it is almost always a scraper site that has copied your content and re-mixed it with the content of another site. People who build sites like that to spam the search engines are not usually too careful with the links.
Unfortunately, Bing Webmaster Tools doesn't tell you where it found the links that it crawled. It only tells you the number of links that it found to your pages. If Googlebot starts crawling these links, then you should be able to find their source in Google Webmaster Tools.