Walnuts are one of the highest value crops in California -- bringing in almost $2 billion every year. But keeping the crop free of destructive insects can be costly.
Scientists are studying if walnut growers could reduce their pest control costs by employing hungry bats.
Sean McNamara is walking toward a white barn at his family’s walnut orchards outside of Winters. "So here are three boxes," says McNamara. He looks up about 15 feet at bat boxes attached to the side of the barn.