Bats prey on insects and can consume as much as their body weight in insects per night. Rachael Long, UC ANR Cooperative Extension farm advisor, discussed how bats protect walnut orchards with Capital Public Radio show Insight  host Beth Ruyak. Long's research has found that each bat provides about $10 worth of pest control savings for walnut growers.

California farmers produce most of the nation's walnuts, about 500,000 tons of walnuts on 290,000 acres, with an annual crop value of $1.8 billion.

Long, who works on field crops and pest control in Yolo, Sacramento and Solano counties, noted...