How does Google determine invalid clicks?

I've received 3 clicks over the past hour but with no increase in my total payment so I'm assuming that Google has deemed them to be invalid. I have not clicked them myself and all my traffic is coming from mostly organic search and forums. So how does Google determine that clicks are invalid? It's frustrating not to be paid for clicks when I'm working so hard to generate good quality traffic. Is there any way for me to know where the invalid clicks came from so that perhaps I can avoid driving more traffic from the same place?

Thanks!

 

Google tends to run a few hours past reality in terms of reporting.

 

google's fraud detection technology is a big hush hush and it looks like you are checking your stats a little too often

 

You caught me

 

They ask me.

Peace,

 

haha aziz

 

They have some aliens working for them at the google's fraud detection center. And they're pretty mean, so watch out.

 

Maybe, u have some click by yourseft hum hum

 

I found that it's waste of time to check the adsense again and again.

 

Yep don't get too caught up in checking stats, watching the money doesn't make it come in any faster