Sentence:  Earlier this month police in Norfolk were called after five hives thought to contain around 60,000 bees and £600 worth of honey were taken. Other known raids this year in Britain have included one in Doncaster in April. Suspicions among beekeepers that the culprits come from their own <WSD>ranks</WSD> were underlined by the fact that a bee smoker was left at the scene by someone who presumably knew that it could be used to calm the insects before taking them. 
Meaning of the word marked with <WSD> tags:  A category of people, such as those who share an occupation.