Should contractors show I.D or wear identifying company clothing?

A current heated discussion on my neighborhood app came up recently discussing if anyone who enters your yard to do work for another company should show identification when asked. The original post involved 2 contractors going to the wrong address, opening up a side gate, and letting a dog off the property. When approached by the homeowner the contractors refused to give an I.D. They also had items in the bed of their truck that did not match their job task so the homeowner found it suspicious and asked neighbors to keep a look out. It turns out they were hired by a neighbor on a different street but the conversation is still going. Some say the homeowner was overly worried some say they should have called the police if they thought it was suspicious. Where do you stand on having someone walk onto your property? Do you question them? What would you do if they refused to identify themselves?

Personally I think it would be easier to give the information a homeowner requests. Have business cards on you to hand out or wear a badge that way the homeowner can call the company you work for to confirm they had employees in the area.