,, here in norther ontario their was 2 choppers searching 3 years ago for crops ,, now their is 4,, if you grow here the penelty is higher if you grow it than if you deel it ,, when they raid your crop they way the whole plant including roots and estimate how much by gram for 20 dollars how much money the crop was worth street value so just getting busted with like 80 -100 big plants would be close to a 1,000,000 dallar bust so they look for any size crop pretty much starting at 20 plants,, they use heat seeking devices you can plainly see just above or on the landing gear, iv heard growing around cedar trees is the best cuz the oils in ceadar trees put out the same amount of heat that a pot plant will,, their was a bust here in northern ontario a couple years ago that was pretty much the biggest bust in canada they found growers had gone to some effort to plant the marijuana in mounds to make them look like potatoes, and that the crop was meticulously cared for. “There wasn't a weed in the field.” OPP and North Bay police officers carried out the raid,dubbed Project Northern Getaway, and found plants in various stages of growth ranging in size from 20 to 60 centimetres. Police say the plants would have had a street value of more than $21 million upon maturity.if you want to read more google ,Q3_2005 web web site opens click Marijuana ,, it was a big bust