Three queen bees and 30,000 bees were stolen in a raid on a farm in Anglesey.
North Wales Police said the bees, which were bred to be “calm”, were taken from three hives on a farm on the outskirts of Cemaes Bay.
Thieves helped themselves to the hives sometime between 30 July and 4 August.
Thieves with a knowledge of bee-keeping are believed to be behind the raid, according to Sgt Gareth Rees, of North Wales Police.
Sgt Rees said: “Bees are currently of national interest and we believe the offender/s knows about bee-keeping.”
He appealed to the bee-keeping community for information relating to the thefts.”
The theft follows a recent warning from NFU Mutual that rural thieves were targeting more unusual items to steal from farms, such as solar panels and bird scarers.
Anyone with information is asked to call 101.