KDVR — Big cities are populated by hundreds of thousands of people, but a larger, hidden population lurks in the shadows.

Depending on where you are in the country, there could be millions of rats just beneath your feet.

Pest control companies can't pin down an exact number of rats in the world but estimate there is about one to two rats per person.

There are roughly 8.2 billion people on Earth right now, which means with a one-to-one ratio, there would be 8.2 million rats. But that number can easily balloon to 16.4 billion with more generous estimates of two-to-one.

There's an old saying........

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