Bats are worth $3.7bn to US agriculture

Amid concerns over the impact of disease and wind farms on bats, researchers are working to quantify the ecosystem benefits of the insect-eaters

California almond grower Glenn Anderson never paid much attention to the bats in his barn, or in his orchard, before the non-profit Bat Conservancy of Coastal California showed up in his part of the Central Valley a few years ago offering farmers bat houses.

The small layered structures provide shelter and breeding areas for bats. Anderson says he was happy to put a few up around his property, but it took a few years for the bats to show any interest. It wasn't until several of his neighbours began planting corn that they seemed to move in for good.