A burglar climbed up a drainpipe to break into a house in Sheffield after a bathroom window was left open.
South Yorkshire Police said the crook struck in Henley Avenue, Norton, during daylight hours.
Officers are also investigating a burglary in Hemper Lane, Greenhill, where a vehicle was reversed into a garage door to gain entry.
A house in Trenton Rise, Woodhouse, was broken into when a front door was left unlocked and homes in Woodthorpe Road, Woodthorpe; Queen Victoria Road, Totley; Holt House Grove, Abbeydale; Chippinghouse Road, Lowfield and St Ann's Road North, Heeley, were raided by burglars who forced, smashed or climbed in through windows.
One burglar removed a door lock to get into a house in Gaunt Way, Gleadless Valley, to steal a boiler and another forced a door to get into a house in Montrose Road, Bannerdale, for the keys to the car parked outside.
A house in Bocking Lane, Beauchief, was broken into when patio doors were left unlocked and garages were raided in Batemoor Road, Batemoor and Havercroft Road, Woodseats.
An investigation is also underway into the theft of a lawnmower from a shed in Birley Spa Lane, Hackenthorpe.
Witnesses to any of the break-ins or anyone with information on those responsible should call South Yorkshire Police on 101 or Crimestoppers on 0800 555111.