As the days get longer and the temperatures warmer, traveling salespeople become more visible in neighborhoods.

Police want to remind citizens to be wary of strangers who come to the door, trying to sell magazine subscriptions or other products.

The city requires door-to-door salespeople to have a peddler’s permit, said Lincoln Police Chief Tom Casady. Charity or nonprofit organizations are exempt.

Travis Barkley, 19, Hershel Totty, 25, of California, and Jonathan Williams, 20, were arrested last week on suspicion of peddling without a permit in the Colonial Hills subdivision in south Lincoln, Casady said.

People are not obligated to talk to peddlers who come to the door, and they should not let strangers into their home, Casady said. He encouraged citizens to call police if someone seems suspicious.