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.
5. Lots of visitors
Keep an eye out for frequent visitors at unsociable hours, or lots of different people coming-and-going at all hours of the day. | South Yorkshire Police
6. How often is the owner seen?
Some cannabis growers use modern slavery or exploit someone to remain at the factory at all times. But another sign is the factory's resident is only seen coming home once or twice a week, as some growers are extremely organised and only tend to the plants a couple of times a week. Picture: PA Archive/PA Images Photo: Matthew Fearn
7. Growing equipment
Look out for potential growers taking lots of plant growing equipment in and out of properties, such as soil/fertiliser and plant waste. Photo by Nottinghamshire Police. | Nottinghamshire Police Photo: Nottinghamshire Police / SWNS
8. Lots of cables and wiring
Cannabis farm set ups require lots of cables and wirings for all the equipment. They may also knock through walls to hastily install air ducts. If wires are still hanging from ceilings/walls after a week, this may be a sign of a grow. Photo: SYP