Police have warned that a suspect is changing a noticeable feature of the house to see if anyone is home.
This could be leaving dirt on front doorsteps to see if it is cleared up or moving or leaving items to check if they are moved.
If the dirt is cleared or the item moved back, it is a warning to the suspect that the residents are home.
But if it is not, police suggest it is a sign the occupant could be on holiday and the house could be a target for burglaries.
The warning comes after a number of burglaries in the Bickley and Sundridge areas.
A Metropolitan Police spokesperson said: “There have been a number of burglaries in the area of Bickley and Sundridge.
“We have been informed that the suspect has been moving/leaving items or putting dirt on the doorstep to see if it is cleaned by occupants, to check if you are home or on holiday.”
Crime prevention advice can be found on the force’s website.
