New Jersey's capital is taking a high-tech approach to rid the city of an estimated 30,000 crows that are waking up residents and leaving behind piles of droppings.

The U.S. Agriculture Department on Tuesday began using pyrotechnics, lasers, spotlights, amplified recordings of crow distress calls and crow effigies to try to scare away the birds from Trenton.

Giaquinto Shoe Repair owner Bob Giaquinto says the crow droppings make a mess out of his store.

“The customers walking in, I’ve got to deal with it on their shoes in here,” he says. “They walk in it, they get it on their shoes, then I get it in here.”

USDA district supervisor and biologist Kimberly Clapper says crows and other birds in the winter form large roosts. Clapper says the crows look for areas where there is less light and few people, such as parking lots.

Officials say that they think the birds came from large landfills in Pennsylvania, just south of Trenton.

Clapper says the methods have worked to clear crows from other urban areas.

USDA wildlife officials will spend four consecutive nights in Trenton until Feb. 23.