Carpet with Flattened Pile?

If you let an ice cube melt on the spot overnight, you should be able to get it to fluff up the next morning. Why this works, I do not know.

Flattened pile occurs in high traffic areas and is a result of the fiber tangling together. There are machines sold for the purpose of detangling, one such was put out by electrolux vaccum company. It consists of floor attachments with plastic barbs that comb thru the fibers. An old fashionioned carpet rake whould help if you dont have an extream amount of floor space to deal with. For one or two very tough spots you could consider using a regular kitchen fork, at doorway entrances or where heavy furniture has been moved from.