Cannabis farms can crop up anywhere - not just in homes but in the back of shops, warehouses and derelict buildings.
On April 5, South Yorkshire Police shared how more than 3,000 cannabis plants were seized in a raid on an empty business on Moore Street, Sheffield city centre.
And, in January, three homes in residential streets in the Burngreave and Pitsmoor area were raided after officers discovered they had been converted into cannabis operations.
When these busts happen and photos are published showing of hundreds of plants in living rooms overtaken with air ducts and wiring, it’s hard not to wonder how they weren’t discovered sooner.
However, cannabis operations can be quite sophisticated in covering up what is happening.
But between the industrial amounts of electricity the operations need, the huge amounts of plant waste and even the efforts to keep what’s happening discreet all leave telltale signs.
Now, police officers have published a list of signs to look for that a home or business in your area has been overtaken by criminals.
See our gallery below for 12 signs to look out for to suggest that a building could have been turned into a cannabis factory.
Report your suspicions to South Yorkshire Police on 101.
1. Strong odours
Strong odours – Cannabis crops take around three months to grow, odours can be potent in the final weeks. Picture by Bedfordshire Police. | Bedfordshire Police Photo: Bedfordshire Police
2. Permanently boarded up or covered windows
Everyone can enjoy their privacy, but if the curtains are always drawn up or even covered or boarded up from the inside it could be a sign of a cannabis factory. | South Yorkshire Police
3. Excessive security measures
There's protecting a home and business, and then there's security measures you might cal "excessive." Look for signs of intense security measures such as extra locks or grilles on windows. | South Yorkshire Police
4. Condensation on windows
Condensation on windows is a normal nuisance for most homes, but lots of condensation, constantly, all-year-round, can be suspect. Cannabis plants need a greenhouse like environment to grow. Look out for condensation on the windows, especially in the summer months. Photo by GettyImages. | Grahamphoto23 from Getty Images