rails 404 error in subfolders in public

it looks for me that crawlers try to resolve the index of all public folder subfolders like "/images/foo", which makes a 404 error. Should开发者_如何学编程 I do something or is this normal?

In your robots.txt

Disallow: /images/foo

Try to keep the crawlers away from anything they don't need in order to make them focus on the things you do need.