They ride in packs, ripping through Baltimore neighborhoods with little regard for traffic laws or common courtesy. Sidewalks are fair game. As are alleys, parks and front yards.
Youngsters and dirt bikes -- a dangerous combination that is of increasing concern to residents tired of being drowned out and run off their streets by what is supposed to be an off-road racing cycle.
Police say some of the riders are drug dealers darting through narrow public housing pathways. Most are teens on speedy joy rides, flouting the law -- dirt bikes are illegal on Baltimore streets -- and evading the police, who acknowledge the scofflaws are hard to catch.
In April, a 6-year-old girl was dragged 46-feet by a dirt bike speeding down a walkway in East Baltimore. Kashmela Johnson spent nearly a month recovering at Johns Hopkins Children's Center.
"When those dirt bikes come, you can't hear telephones, you can't hear doorbells, you can't read," said Ann Nichols, who lives on Pulaski Street in West Baltimore. "They are the most dangerous things made. I pray to God every day that someone stops them."
The plague of dirt bikes is hardly new -- and is not limited to the city -- but police and residents complain of the increasing brazenness of the young riders.
"The problem has been here ever since the invention of dirt bikes," said Capt. Michael P. Fitzgibbons of the Anne Arundel County Police Department. "It's gotten to the point now where the community doesn't want to stand for it anymore."
In Anne Arundel and Baltimore, as in most jurisdictions, dirt bikes are allowed only on private property.
In Baltimore, the City Council passed a law last year requiring dirt bikes to be registered, and police say they try to seize the unregistered cycles from homes where they are stored. The department even bought two off-road motorcycles and are using them in South Baltimore.
"It's very difficult to enforce," Col. Leon N. Tomlin, chief of the neighborhood patrol bureau, said at a City Council hearing in May. "They are kids. If you chase them and they hit something, they are going to get killed. . . . The only thing that can catch a dirt bike is a dirt bike."
Mayor Kurt L. Schmoke even took time at a recent news conference to warn residents that police would start an aggressive campaign. "We will go and seize these bikes and actually take them from the owners," he said. "Just trying to chase them isn't enough."