What is the proper noun in a row of ants marched across the picnic blanket?

In the sentence "A row of ants marched across the picnic blanket," there are no proper nouns present. A proper noun is a specific name for a person, place, or organization, such as "John," "Paris," or "Microsoft." The terms "row," "ants," "picnic," and "blanket" are all common nouns.