How many illegal immigrants are there?

The lowest number reported is 11 million with totals going as high as 20-30 million. My gut feel is 20 million. I think we had millions more that returned home because they were just economic raiders, not true immigrants. Why do I say this? Metro Atlanta probably has 200,000 illegals. Just count up all the restaurant jobs, landscaping, construction, etc... And take a look around you at Walmart, grocery stores, etc... But it's not just the major Metro cities that have a huge influx of illegals. All you have to do is to go to small towns where there is meat processing (cattle, poultry, hogs) or go to the oil fields. There are illegal workers providing elder care, maid service, baby sitting. Not to mention the migrant workers and farm hands, ranchers etc... Aye Caramba!