ecological benefits of Bats

there is growing evidence that bats play vitally important ecological roles which may also have significant economic benefits.Bats are the major predators of night flying insects Co-operative Extension Farm adviser from the university of California,Rachel Long found that agricultural pest featured prominently in the diet of Bats.In another study done by Long,reported in the new scientific magazine,California, pear farmers suffered crop losses of less than 5% dew corn ear moth when a bat colony was situated 2km away,crop losses of 60% were reported when the bat colony was located 4km away in other words the presence of sufficient Numbers of bats reduced crop damage by 55%.closer to home South Africa's largest colony of 300 000 bats occupying De Hoop Guano Cave assist farmers in the Bredasdorp area by consuming approx 100 tonnes of insects annually,including many crop pests each growing season, so instead of eradicating bat colonies from farm house farmer are now finding ways of attracting bats to their fields by erecting bat houses.(Bats of southern Africa by John Tylor)
we had also considered keeping bats after experiencing a devastating attack of the Chillo patellas spoted stalk borer.WE had put one Bat house on one of our northwest facing walls and we are expecting bats to roost in it soon.