Police are urging residents in south Sheffield and north Derbyshire to take extra security measures to beat the burglar after a spate of break-ins.
Derbyshire Police said there had been a significant number of thefts since November last year - including a spate of nine incidents within two weeks from late December to early January.
Homes have been targeted in Summerfield Road, Dronfield; Cross Lane, Appletree Drive, Longacre Road, Fairview Road and Longcroft Crescent, Dronfield Woodhouse and Holmley Lane, Coal Aston.
Officers in the burglary unit are now encouraging residents to ensure their homes are as secure as they can be.
Detective constable Peter Gore said: “The properties that have been broken into have mostly been empty at the time.
Thieves have targeted houses that appear vacant between 4pm and 9pm.
“Residents can take a number of steps to ensure their property is secure and it looks like someone is at home. This could include using timers for lights so they come on to make the house look occupied.
“If you have a house alarm ensure that it is activated, door alarms are also available which sound when the door is opened.
“If you are going away ask a neighbour to keep an eye on your property and put your dustbins out for you.”
Anyone with information about burglaries in the area is asked to contact DC Gore on 101.