A beekeeper is appealing for help to trace about 30,000 honey bees which have disappeared from a hive he operates in south Worcestershire.
The bees could set up home in a barn or chimney
They were last seen at Nursery Close, Pershore, on Thursday evening.
Police said the bees could cost £100 to replace and the owner cannot explain why they suddenly left their home.
People are being asked to report if they see any swarm and are being warned the bees are likely to set up home in old chimneys, barns and trees.
A West Mercia Police spokesman said: "The bees could have travelled in any direction.
"The owner cannot explain why they suddenly left their home, where there is a second hive, which remains stable."
Anyone with information is asked to contact police.