Patrols are being stepped up by police in Thorne, Doncaster, after a spate of shed break-ins.
Officers are concerned that householders do not give adequate protection to the valuable items in their outbuildings.
Sheds can easily contain more than £1,000 of gear which is more vulnerable because of the structure of the buildings. Three were targeted in one night on Wednesday into Thursday.
Raiders got into a shed in Brooke Street by removing the door hinges and got away with £500 of power tools, a £400 lawnmower, and a strimmer which was valued at £80.
Another lawnmower, worth £200, was taken from a shed in Foster Road after the lock was forced.
And the padlock of a shed in Millcroft Close was forced in the night so the thieves could steal a mountain bike valued at £400.
Supt Eddie Murphy, of Doncaster police, said: “People need to ask themselves, ‘Do I know the value of the property in my shed?’. Because it adds up to more than people think.
“Fishing tackle can cost thousands of pounds and yet be stored in a shed with just a lock and where the hinges can easily be unscrewed.
“I would advise people to consider a separate burglar alarm for the shed, or have it linked remotely to the house alarm.”