NEW YORK - THERE must be 50 ways to get rid of pigeons, but not 50 effective ways. New Yorkers have tried broadcasting falcon shrieks, installing beach balls painted with big eyeballs, posting fake owls on cornices, strewing mothballs on roosts, even using Avitrol, a hallucinogenic avicide now outlawed in the state, which made birds "go on a bad trip," persuading their peers to stay away.

Those spikes that frustrated landlords install on window sills? The birds will build nests in the middle of them, according to Heath Waldorf, vice president of Bell Bird Control, based in Parsippany, N.J. His company's brochure features a portrait of a pigeon perched saucily atop a fake owl.

Mr. Waldorf believes he has an answer: the BellStrip, which gives a nonlethal shock to birds that land on it, and has been installed on the General Post Office near Pennsylvania Station, Staten Island University Hospital and other health care centers that wished to remain anonymous. It has also been placed along the pipes, conduits and other popular roosts aboard the Intrepid Sea, Air and Space Museum.

Nuisance pigeons, a phrase straight from the Department of Redundancy Department, can spread disease through their feces, which include uric acid that can corrode paint and metal. Their waste can also make outdoor eating areas unsanitary, land on unsuspecting tourists and, in the Intrepid's case, ruin the surface of a perfectly good aircraft carrier.

"The strips, which include wires attached to a solar-powered battery, produce enough of a shock to goose a goose, but they do not harm birds or humans", Mr. Waldorf said.

He said the strips had been installed on 20 percent of the ship's port side, and 60 percent of the sunnier starboard side favored by birds.

Matt Woods, vice president for operations and security at the museum, said, "The Intrepid sought to deal with this issue in a safe, effective and humane way to accomplish the goal of a safe and enjoyable environment for our museum visitors."

A competitor of Mr. Waldorf's - one he declined to name - has started a "re-education program," rounding up pigeons, transporting them to the hinterlands and marking orange stripes on their backs so that they can be easily identified (and exterminated) if they return to the city, he said

Across the street from the Intrepid, on top of a semi trailer, a passel of pigeons, some with orange stripes painted on their backs, staked out H&H Bagels on 46th Street, probably unaware of what fate may await them.