Bots don’t¹ blindly follow all links on a page.
A bot remembers the URLs it has crawled and the URL it is currently crawling. If it finds a link to one of those URLs again (something which happens all the time -- think of the site navigation, for example), there’s typically no need to crawl it again for some time.
¹ Well, technically they could, of course. And there are likely some peculiar/bugged bots out there that do this. But it would not only waste your resources, also the bot’s. So bot providers have a reason to make their bots "smart": saving costs.