Trouble with bees

Australian bees are doing very nicely. But unless we're careful problems plaguing American hives could turn up here. There are several theories on why colonies are collapsing in the US. Is it because the bees are overworked and poorly managed - or is the bug called varroa destructor the cause of the problems. Quarantine is tight to make sure it doesn't enter Australia as a stowaway. Reporter Stan Correy.