Most important? Your safety.
There are lots of scams out there where people are pretending to be census workers. The number one way you can avoid a census scam is to adhere to the deadline on the census letter you receive in the mail. Finish the survey and you will remove yourself from the list of non-participants. If you are every in doubt about the legitimacy of a census worker, visit this website: https://www.census.gov/about/regions/denver/contact/identify.html
Call the Denver Regional Office for verification at 1-800-852-6159. Office hours are Monday through Friday, 7:00 a.m.- 4:30 p.m., Mountain Daylight Time.
The City of Delafield will post more reminders about census workers as the time approaches.