There was a bit about them in todays (sunday ) mail seem to be a bit of a pest causing some damage to commercial fruit crops . I was lucky and arranged an evening visit (after the park closed) To Kelsey park in Beckenham sth london with our cub pack and as dusk fell there must have been over 200 birds flying in to roost There is also a very large colony of herons who returned from the raids on the local ornamental ponds . The main purpose of the visit was to see the large population of bats whish we were able to observe with the aid of a powerfull beam shining across the lake and of course the "Bat detectors " picking up the "clicking" ulstrasonic sounds. a grean evening out