This April 5, 2020, file photo shows an envelope containing a 2020 census letter. Credit: Paul Sancya / AP

The U.S. Census Bureau is following up with Maine households that have not yet responded to the 2020 census.

Workers began in-person visits Thursday to households that have not yet responded. The first visits will be focused on six locations — West Virginia, Idaho, Maine, Kansas City, New Orleans and the Oklahoma City area.

The current self-response rate in Maine is 53.6 percent. Nationwide, about 56 million households that have not yet responded to the 2020 questionnaire.

Because of the virus, census workers wear cloth face masks and come equipped with hand sanitizer, gloves, laptops and cellphones. They will ask questions from outside, and aren’t allowed in homes.